[N90] 1. Photo-Optical System Description

This section briefly describes and outlines the operational capabilities of the launch operations area (LOA) photo-optical system used at KSC. The subsystems that make up the LOA photo-optical system are listed in the following table.

Figure 145 shows the location of all cameras on the MLP and fixed service structure, and table 18 lists pertinent camera and film data for the MLP and FSS cameras. All of the technical documents/drawings (maintained and nonmaintained) associated with the LOA photo-optical system are listed in the System Documentation List, 79K11142, which serves as the top Operation and Maintenance Documentation system definition drawing. This list identifies the specific documents/drawings that comprise the maintained Operation and Maintenance Documentation.

The function of the LOA photo-optical system is to operate still and motion picture film cameras located at various areas on launch complex 39 (LC-39). The system consists of equipment located in the following areas: Launch Control Center (LCC) room IP6, pad A and pad B, pad terminal connection room (PTCR) room 207, FSS, MPL, and at the pad perimeter camera sites. The system consists of the following subsystems:

LCC camera control system

Pad camera control system

Timing system

Emergency camera control system

Power subsystem

Camera mounting system

Gaseous nitrogen (GN2) purge system

Two camera trackers are located on LC-39: one on perimeter camera site 2 and one on perimeter camera site 6; these trackers are remotely controlled from room IP9 of the LCC.

a. System Components

(1) LCC Camera Control Systems

The two LCC camera control systems have the capability of initiating 320 control (on-off) signal "starts" over 320 channels. LCC camera control systems I and 2 have 160 channels each. The control signals can be automatically initiated simultaneously or sequentially at predetermined intervals or started manually. The photo-optical system is basically automatically sequenced with provisions for manually overriding the automatic control. Each LCC camera system consists of the following components:

Camera control panels

Camera control patch panels

Camera control sequencer and sequencer control panel

Sequencer synchronizer control panel

Events programmers and patch panel

Control multiplexers

Status demultiplexers

Wideband line patch panel

 

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[N91]

Figure 145. General View of FSS and MLP Camera Locations.

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Emergency camera control (ECC)

panel ECC distributor and patch panel

ECC firing room (FR) selector panel

Firing room ECC panel

Power supplies

(a) Control Signals

The photo-optical system camera control signals can be automatically sequenced into 100 start and stop times, which are turned on and off at preselected times by the camera control sequencer. The camera control sequencer feeds the control signals in parallel form to eight multiplexers. The multiplexers serialize the control signals into return-to-zero (RZ) data trains, which are fed to data modems. The data modems convert the signals into a dc level shift data train which is distributed to the demultiplexers. Each multiplexer/demultiplexer (mux/demux) channel sends 40 lines of on-off information used to energize relays in the camera control repeaters (CCR's) which apply power to the camera motors.

 

(b) Camera Control Panel

The photo-optical system has 16 camera control panels in the LCC at LC-39. Eight camera control panels are for LCC camera control system I, and 8 camera control panel were for LCC camera control system 2. Either camera control system may be used, with appropriate patching, to control either pad A or pad B. Each of the camera control panels has 20 three position switches which are used to initiate the camera control signals. The switch positions are SEQON, OFF, or MAN ON.

-SEQ ON position provides -28 V dc enable voltage to the camera control sequencer and allows the channel to be turned on and off at the programmed time.

-OFF position inhibits the channel, except that the emergency camera control subsystem can turn the channel on with the switch in this position.

-MAN ON position is the manual override.

-The camera control panels used for each LCC camera control system are identified with camera channels and are numbered from top to bottom and left to right with numbers I through 160. The camera control panel three position switches are backlighted with colored filters for the following three positions:

-MAN ON (up) position-red OFF -(center) position-white

-SEQ ON (down) position-green

The lamps are lighted when there is a status output from the status demultiplexer, thus indicating that ac voltage is present at the output of the unique camera control repeater serving a given camera.

 

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[N92]

Table 17. Pertinent Camera and Film Data for MLP and FSS Cameras.

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(c) Camera Control Sequencer and Sequencer Control Panel

Each photo-optical camera control system utilizes a photo-optical system camera control sequencer- Astrodata model 6575-523-1. The camera control sequencer consists of up-down counters and logic circuitry used in conjunction with the event programmers and patch panel to turn the camera channels on and off. The sequencer control panel contains the

 

(d) Events Programmers and Patch Panel

Each photo-optical camera control system has two events programmers and one events patch panel. One programmer in each camera control system is designated as "continuous" and controls events 1 through 25, and the other programmer is designated "discontinuous" and controls events 26 through 50. A hold in the sequencer count will turn off a "discontinuous" event, but a hold will not turn off a "continuous" event. The events programmer has two sets of thumbwheel switches for each event to establish the start time and stop time for each event. With the event programmer thumbwheel switches set for a start time and a stop time for an event and when the sequencer countdown time reaches the thumbwheel setting for start time, the event is turned on. When the countdown time reaches the thumbwheel setting for a stop time, the event is turned off. An event can control any number of channels as determined by patching at the events patch panel. The events patch panel has two jacks wired in parallel for each event and camera channel. This configuration allows "daisy chain" patching; all channels patched to a single event will be started and stopped at the same time.

 

(e) Control Multiplexers

Each LCC camera control system uses four Astrodata model 6555-516-1 control multiplexer/status demultiplexers for both command and status functions. The control multiplexer serializes the on-off information (40 lines) received from the camera control panels and camera control sequencer. The control multiplexer generates a 48-bit data word which contains 7 bits for frame reference, 1 bit for loop check, and 40 bits of camera on-off information. The 7-bit frame reference is a selfcheck feature design to prevent noise from interfering with normal control-circuit operation. Each frame reference is compared with the preceding frame reference and must be its complement; if it is not its complement, then the multiplexer will not transmit any camera control data.

(2) Timing Subsystem

The timing subsystem includes the timing distributor, a timing terminal unit, and associated cabling. Timing signals are applied to each engineering camera so that time correlation of the exposed film may be identified. The serial timing inputs are applied to an illumination block where a standard Inter-Range Instrumentation Group (IRIG) format timing code is exposed on the edge of the moving film.

 

[N93] (a) Timing Distributor Panel

The timing distributor serves as the monitor and distribution for the photo-optic IRIG bipolar timing signals (TRIG-A, -B, -H, and -E). Jacks are also provided for monitoring the CCR control input lines. Timing distributor panels are located at pad A and pad B perimeter B site camera timing and control (CTC) boxes and the PTCR-B room 207.

 

(b) Timing Terminal Unit

The timing terminal unit (TTU) accepts IRIG bipolar-timing coded signals from the KSC timing subsystem through the timing distributor panel. The TTU circuitry processes and converts the bipolar signals into a dc level-shift signal of sufficient amplitude to drive a light-emitting diode (LED) in the camera. This LED exposes the edge of the film to the coded timing signals. An LED monitor on the TTU provides a meter which indicates the current being drawn by the LED. Switches are provided to select the camera channel being monitored and to monitor the LED currents. Each of the ten LED driver circuits in the TTU produces no output until an enable signal (a ground) is received from its corresponding channel in the CCR. (The "enable signal" is simply providing a path to ground through a set of normally open (NO) contacts in the CCR.) Normally, the enable signal is generated in the CCR when the channel is activated by the camera control system. A switch is also provided on the TTU to operate the enable signal internally for checkout and calibration purposes. TTU circuitry power is furnished from a plug in power supply mounted on the TTU chassis.

(c) Control Demultiplexers

The photo-optical system control demultiplexer is contained in the Astrodata model 6555-515-1 camera status multiplexer/demultiplexer, and the status multiplexer is part of the same unit. The control demultiplexer converts the pulse code modulation (PCM) signal received from the data modems into 40 on-off signals in parallel form after having verified the frame reference word. The demultiplexer outputs (40 lines) are routed with a -28 Vdc line from the demultiplexer/multiplexer power supply to the camera control repeaters via the buffer relay panel. The CCR's use these signals to energize relays which connect ac power to the camera motors. A ground on the demultiplexer output line will energize the CCR relay.

 

(d) Camera Control Repeaters

The photo-optical system camera control repeaters are two types: single-phase Astrodata model 6550-547-1 which will operate ten single-phase cameras; and three-phase Astrodata model 6550-548-1 which will operate five three-phase cameras. The CCR connects single-phase or three-phase ac power to the camera motors when a start signal is received from the control multi-plexer. The CCR generates the status signal inputs and sends the signals to the status multiplexer. The CCR also furnishes an enable signal to the TTU which turns on the timing signal to the camera. The CCR can operate cameras locally by switches on the CCR front panel, or the CCR can be programmed so that the cameras can only be operated remotely.

(e) Status Signals

The photo-optical system status signals are generated in the CCR. The logic term senses the presence of 120 Vac across the circuit supplying voltage to the camera motor winding when the channel is on. The logic term is routed to the status multiplexer, and a status output signal is generated in the status multiplexer output.

The status signals activate lamp drivers in the LCC status multiplexer which turn on lamps in the camera control panel switches. The console operator, by observing the lights and switch positions, can determine when and where the cameras are running. The status signals are transmitted to the LCC by standard communications cables.

(3) Emergency Camera Control Subsystem

Each emergency camera control (ECC) subsystem (one per photo-optical system) provides for overriding the camera control system by turning on all channels selected for emergency "starts" with one switch located on pad safety consoles in firing rooms 1 and 3. Once actuated, the ECC subsystem will keep the emergency cameras running for either one minute (mode II) or 15 minutes (mode b, depending on which mode is programmed and assuming the switch remains in the start position. At the end of the programmed ECC cycle, control of the camera channels is returned to the camera control system. Each ECC subsystem includes the following units:

ECC mode selector panel

ECC FR selector panel

2 ECC distributor and patch panel ECC power supply

Firing room ECC panel

 

(a) ECC Mode Selector Panel

The ECC mode selector is on a panel located in LCC room IP9. The MODE I/MODE II switch provides for the 1-minute or 15-minute emergency-run cycle. In mode I, the cameras run for 15 minutes and stop automatically; in mode II, the cameras will run I minute and then stop automatically. A READY indicator lights when the ECC system is enabled by turning on the ECC power supply. The EMERGENCY indicator flashes at 2 pulses per second (PPS) when the selected cameras are activated in a firing room by the START/OFF switch on the ECC panel. Once activated, the EMERGENCY indicator will flash until extinguished by the RESET switch (provided that the START/OFF switch on the FR ECC panel is returned to the OFF position).

 

(b) ECC FR Selector Panel

The ECC FR selector is used to select one of the firing rooms for operating the emergency cameras at the pad areas. When the system I DISTRIBUTOR switch is in the FR I position, firing room 1 has control over the designated system 1 cameras; when it is in the FR 3 position, firing room 3 has control over these cameras. The system 2 DISTRIBUTOR switch operates in a similar manner for designated system 2 emergency cameras.

 

(c) ECC Distributor

Distributor contains the relay logic for control of the designated emergency cameras. This distributor is equipped with indicators which display the mode position in programmed to operate to indicate when dc power is applied to the subsystem and to indicate when the emergency cameras are running by flashing the EMERGENCY light. This flashing light can be turned off only by actuating the RESET switch on the ECC mode selector panel or by turning off the ECC power supply.

The ECC distributor emergency light is wired in parallel with the ECC mode selector panel emergency light (will operate simultaneously). The ECC distributor contains the matrix board used to patch the selected emergency cameras. Pin plugs are provided for insertion in any of 160 jacks on the matrix board which represent up to 160 camera channels at the multiplexers. Placing a mode I pin in any of the matrix jacks will cause that channel/camera to turn on and off when emergency mode 1 is switched. Mode II pins work in the same manner for emergency mode II operation and also turn on all mode I cameras.

(d) ECC Power Supply

The ECC power supply provides power for the entire ECC system. The power supply panel contains two power supply modules which provide redundancy in case one of the modules fails. The outputs of each supply are routed to a diode gate in the ECC distributor which allows one or the other supply to provide power. Indicator lights on the power supply front panel show which supply is supplying the subsystem power.

 

[N94] (e) FR ECC Panel

ECC panels are located on the FR pad safety consoles in firing rooms I and 3. This panel contains the switch which activates the ECC subsystem. Included on this panel are indicators showing READY (dc power on), mode I or mode II (the operational mode of the ECC subsystem), and RUNNING (emergency).

(4) Power Subsystem

The power subsystem consists of the ac power panels, circuit breakers, ac strips, and power cabling. Single- and threephase fuse panels provide protection for camera motors. Singlephase fuse panels are in series with single-phase CCR outputs, and three-phase fuse panels are in series with three-phase CCR outputs.

(5) Camera Mounting Subsystem

The camera mounting subsystem encompasses hardware used to mount cameras on the pads, perimeter sites, and MLP's. The mounting equipment is used in various combinations to achieve the required fields of view with a minimum of vibration. The following hardware units are used in the camera mounting system:

Perimeter pedestals

Abutment pedestals

Pan-and-tilt mounts

Mobile tracker

MLP mounts

Wedges

Environmental housings and covers

(a) Perimeter Pedestals

Each perimeter site has four 6-inch-thick concrete pads which are flush with the road surface. Each pad will accommodate, and has provisions for bolt-stud mounting for four fixed pedestals of various heights (30 to 48 in.). The pedestals are welded aluminum structures with adapter plate welded on top. Each pedestal is grounded to a system ground cable. The adapter plates, welded to the site pedestals, are made from 1-inchthick aluminum, coated with an electrically conductive and corrosion-resistant material. The adapter plate is drilled to accept wedges, pan-and-tilt mounts, environmental housings, or Hi-Hat Mitchell-type heads.

 

(b) Abutment Pedestals

Abutment pedestals are used for mounting long focal-length-lens cameras. Each perimeter site has four of these 24-inch high concrete structures.

 

(c) Pan-and-Tilt Mounts

Pan-and-tilt mounts provide a camera mounting surface that is adjustable in both azimuth and elevation. Pan-and-tilt mounts for LC-39 photo-optical use are mounted on adapter plates or wedge mounts. The maximum elevation angle adjustment without wedges is - 15 to + 60 degrees. The azimuth rotation is 360 degrees. Each pan-and-tilt mount has an 8-inch by 12-inch table which adapts to wedges, dovetail mounts, or camera explosion-proof housings. Both elevation and azimuth angle adjustments are secured with locking bolts provided with the pan-and-tilt mount.

(d) Mobile Tracker

A mobile Goertz tracker unit is positioned at each pad (A and B) at perimeter camera site 2 to support photooptical launch operations requirements. Each mobile tracker unit is remotely controlled from a manually operated joy stick control console in LCC room IP9. The mobile tracker units provide for tracking a launch vehicle from lift-off to the limit of the camera lens capability installed on the tracker. Visual tracking of the vehicle is through use of television boresight cameras. Control and monitoring of the television cameras is accommodated at the photo tracking consoles in LCC room 1P9.

A tracker control cabinet (TCC) and an operational television distributor are installed at both pads at perimeter site 2. The TCC distributor provides the control and timing required for the photo-optical cameras mounted on the mobile tracker. The operational television distributor provides the control and picture interface required between the mobile-trackermounted boresight television camera and the LCC room 1P9 camera controls or monitors.

Both mobile trackers can have up to five adjustable wedge mounts located between the photographic cameras and the special tracker platforms. These mounts provide a predetermined target orientation for each photo camera. Two heavy-duty clamps secure the boresight camera to a predetermined axis point. All mobile tracker photo-optical cameras are referenced to this axis.

 

(e) Mobile Launcher Platform Mounts

Cameras installed on the MLP zero or blast deck use environmental housings and covers mounted on adjustable mounts designed with a -10-degree elevation adjustment. Bases for these mounts are available in fixed 10-degree increments between O and 60 degrees. The elevation is predetermined within the 10 degrees of movement provided. After the desired elevation position is determined, the mount assembly is secured with bolts threaded into the base. The azimuth axis is determined and fixed prior to welding the base brackets to the MLP decks.

 

(f) Environmental Housings and Covers

Environmental housings are used over cameras in flame-impingement areas. Cameras in sustained flame areas are provided with an additional protective cover of stainless steel and ablative coating. The environmental housings are sealed and purged with gaseous nitrogen with provisions for gaseous nitrogen flow around the glass portion of the housings to cool the glass and to disperse water from the glass surface.

(6) Gaseous Nitrogen Purge Subsystem

The environmental camera housings used on the fixed service structure and the MLP incorporate a continuous gaseous nitrogen low-pressure purge of 50 psi during hazardous operations. During launch, a separate high-pressure, 750-psi gaseous nitrogen supply is used for window purge. A separate start signal is provided for the high-pressure gaseous nitrogen purge, which is sequenced with the camera start signal. This purge-start originates from an independent 28-V-dc power supply and associated relay panel located in PTCR room 207, rack 5337.

 

b. Theory of Operation

The following paragraphs explain the operation of the photo-optical control and status subsystem. The sequence is that which occurs with the initiation of a control signal (START) through the multiplexing, transmission, demultiplexing, and repeater stages to the actual camera start. The loop is completed by tracing the status signal from the CCR through the multiplexing, transmission, and demultiplexing stages to the display of status information on the camera control panels.

(1) Initiation of Control Signals

Control signals are those signals, which, after having been conditioned, ultimately turn on cameras. Control signals are generated in the camera control panels and in the ECC distributor by relay closures applying grounds to the multiplexer inputs. Camera control signals are referred to as camera start commands, or more simply, as "starts." The automatically sequenced control signals consist of-6-V-dc signals generated in the continuous and discontinue register output logic. These outputs are routed through the events patch panel to the camera control output gates. Reference the Astrodata manual for additional discussion of the sequencer operation.

There is an OR gate for each of the 160 camera channels. The OR gate will have a high output (near -6 V dc) which represents an ON input to the multiplexer (through an inverter) when either of the following conditions exist (see figure 146):

 

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[N95]

Figure 146. Camera Control Output Gating (Negative Logic).

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- The switch on the camera control panel is in the MAN ON position and is supplying - 28 V dc (manual override signal) to input 1 of the OR gate (high output).

- The switch on the camera control panel is in the SEQON position supplying - 28 V dc (sequencer enable signal) to input 1 of the AND gate, and - 6 V dc from the events register output logic is present at input 2 of the AND gate simultaneously (high output). If either of these signals is not present, the output of the AND gate will be low and the input to the multiplexer will be OFF.

(a) Automatic Control

Automatic, or sequencer, control is initiated when the sequencer up/down counter reaches the count which has been preset into the START TIME thumbwheel switches of the continuous or discontinuous programmers. Each programmer contains 50 five-section thumbwheel switches. Twenty-five of these switches in the continuous events programmer are used to preselect the start times of up to 25 events (camera starts) which will not be interrupted during a hold. The other 25 switches preselect the stop times for the same events. The discontinuous events programmer switches serve the same purpose, but these events will turn off during a hold and turn on again when the count proceeds.

Each switch has five sections. From left to right, the sections will select: (a) + for countup or - for countdown, (b) hundreds, (c) tens, (d) units, and (e) tenths of seconds. When the sequencer up/down counter reaches the time which has been preset into the START TIME switches, the output of the switch will be 0 V dc, or ground. This output will enable the logical set enable input of a 100 kHz common clock flip-flop in the event output logic, and the flip- flop will set on the next positive-going pulse from the sequencer clock purser. When the flip-flop sets, its output will go to 0 V dc. The flip-flop output is inverted in the events register, causing -6 V dc to be routed (through the events patch panel) to the AND gate input 2 of the output control logic shown in figure 146. The STOP TIME thumbwheel switches of the programmers operate in the same manner except that their output is applied to the logical reset enable input of the flip-flop causing the flip-flop to reset on the next positive-going pulse from the clock purser. The action is then reversed, and the events register output for the event is low (0 V dc) at the AND gate. The AND gate (figure 146) can have a high output only when both the -6 V dc (sequenced event signal) and the -28 V dc (sequencer enable signal) are present simultaneously. The sequenced event term is generated as described previously, and the sequencer enable term is generated by placing the switch on the camera control panel in the SEQUENCE ON position.

(b) Manual Override Control

Manual control of a camera channel is initiated by placing the switch on the camera control panel in the MANUAL ON position. In this case, -28 V dc is applied to input 1 of the OR gate (figure 146), and the sequencer enable signal is no longer present at the AND gate input 1. The AND gate output is now low and the B camera control panel is controlling....

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[N96]

Figure 147. Emergency Control Operation Simplified Schematic.

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....the camera channel, regardless of whether or not the sequenced event term (-6 V dc) is present at the AND gate input 2; therefore, the manual control at the camera control panels overrides the sequencer control as stated in b.(l)(a).

 

(c) Emergency Camera Control

Emergency camera control overrides both manual and sequencer control. Equipment involved includes the ECC mode selector panel, the panel, the ECC panels in firing rooms 1 and 3, the ECC distributor, and the ECC power supply. The emergency control signals are generated in the ECC distributor and applied to the multiplexer inputs by means of a tap or "Y" arrangement in the cables between the sequencer and multiplexer. When the ECC system is activated, a ground (0 V dc) is placed on each channel which has been designated as emergency, thus turning the channel on, regardless of any other control signal on the line.

Mode 1 Operation. Assume that the ECC distributor has been programmed as desired, and that the ECC system is to be operated in mode I (15 minute run time). The ECC power supply is turned on and the MODE I/MODE II switch on the ECC mode selector panel is in the MODE I position (the DC POWER and MODE I indicators will light on the ECC distributor). When the start switch on the FR ECC panel is closed, + 24 V dc power is applied to the coil of K47, to the coils of relays K1 through K41 through the normally closed (NC) contacts of time delay relays DL1 and DL2, and also to the coil of DL1 through the normally cosed (NC) contacts of K42 (see figure 147). Relays K1 through K41 energize and the following events occur simultaneously.

-The normally open contacts of K1 through K40 close and connect the multiplexer input lines to the ground bus (-D) in the ECC distributor.

-The NO contacts of K41 close and apply power to the coil of K43.

-K43 energizes.

-K43 is locked in the energized state by it NO contacts.

-The K43 NO contacts close and apply power to the 2 PPS flasher K44 (DS5) and to the EMERGENCY indicators in the ECC distributor and ECC mode selector panel.

-The EMERGENCY indicators begin to flash.

-The DL1 time delay (15 minutes) is initiated.

The programmed channels will continue to be on until DL1 energizes or the START switch is turned OFF. When DL1 energizes, its normally closed contacts open and remove power from K1 through K41 and the above action is reversed except that K43 remains energized and the EMERGENCY indicators continue to flash. The EMERGENCY indicators can be extinguished only by pressing the RESET momentary pushbutton switch on the ECC mode selector panel or by turning off the ECC power supply to remove power from the coil of K43. When K43 deenergizes, its NO contacts open, and releasing the RESET switch cannot apply power to the coil.

Mode II Operation For mode II operation, the MODE I/MODE II switch on the ECC mode selector panel is placed in the MODE II position. This setting will apply a ground to the coil of K42 (see figure 147) and cause it to energize. The K42 NO contacts will close, lighting the MODE II indicators, and the NC contacts will open, extinguishing the MODE I indicators and connecting deck no. I of the matrix board to ground. It should be noted that any channels that are programmed for mode I will also operate in mode II because deck 2 is tied directly to the ground bus.

(2) Programming

Before the timing and control subsystem can transmit control signals, programming must be accomplished. Equipment to be programmed is the continuous and discontinuous events programmers and the various patch panels. The following paragraphs explain the operation of these devices.

(a) Control Switch Patch Panel

The control switch patch panel provides a means of selecting the channel that a given camera control switch can control. Figure 148 illustrates how this is accomplished.

The patch panel (AMP 1632) contains 1632 jacks arranged in 48 vertical columns and 34 horizontal rows. For purposes of this discussion, the jacks will be referred to by their schematic (63E910179) callous, consisting of a letter representing the column and a number representing the row. For example, the fifth jack in the tenth row is referred to as E10. Actual callouts on the panel are as shown in the pictorial view of figure 148. The large blocks at the top of the panel are connected to the sequencer camera control output logic. The number in each block represents the multiplexer channel to which it is connected. The two jacks on the left (wired in parallel) are connected to input 1 of the camera control output logic OR gate. The two center jacks supply the sequencer enable voltage to input I of the AND gate and the jacks on the left are the status output from the status demultiplexer.

The group of small blocks (beginning with row 21) on the patch panel access the camera control panel switches. The number in each block represents the control switch to which the jacks are connected. The jack on the left in each block is....

 

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[N97]

Figure 148. Control Switch Patch Panel Simplified Schematic.

Figure 149. Events Patching Signal Flow Diagram.

Figure 150. Camera Control and Status Subsystem Functional Diagram.

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[N98]....connected to the manual control terminal and the center jack is connected to the sequencer terminal of the switch. The jack on the right is connected to the switch indicator lamp (see figure 147). The group of blocks numbered 1 through 16 at the bottom of the panel are connected to the 16 switches on the momentary control panel in the same manner as the camera control Panel switches, except that the center jack in each block is not connected. When programming this panel, it must first be determined which mux/demux channels are to be controlled by each switch. Patch cords are then connected between the switch jacks and the mux/demux channel jacks as shown in figure 148. When a switch is to control more than one channel, patches from one mux/demux channel to the next are made in daisy-chain fashion.

It should be noted that parallel patching at the control switch patch panel is not desirable because it could produce an erroneous status indication at the camera control panels. If two camera channels were patched to the same control switch and one of the channels malfunctioned in the CCR, then the camera control panel indicator would still light if the other channel functioned properly. For this reason, any parallel usage of camera channels should be done on the events patch panel.

(b) Events Programmers

Both the continuous and discontinuous events programmers are operated identically; therefore, only the continuous events programmer will be discussed. The continuous events are numbered 1 through 25 and the discontinuous events are numbered 26 through 50. Each event has a START TIME thumbwheel switch. The countdown time which the event is to start and stop is set into the appropriate switch by turning the five thumbwheels on each switch until the desired numeral appears in the window of each section.

 

(c) Events Patch Panel

The outputs of the switches on the continuous and discontinuous programmers are patched to camera control output logic at the events patch panel. Figure 149 shows the signal flow. The patch panel has two groups of jacks. The group on the left is used to patch the continuous events, and the group on the right is used to patch the discontinuous events. In the continuous events side, the jacks are grouped in pairs enclosed in rectangles. The large sections of rectangles at the top, center, and bottom of the panel (CAMERA CHANNELS), numbered 1 through 160, are the output jacks which are routed over 160 lines to the camera control output logic in the sequencer. The two smaller sections of rectangles (EVENT OUTPUTS), numbered 1 through 25, contain the input jacks from the events register in the sequencer. Within each rectangle, the two jacks are wired in parallel to provide for paralleling channels as desired. The discontinuous events (right-hand) side of the panel is identical to the continuous events side with the exception of the event numbers. In addition, the CAMERA CHANNELS jacks are wired in parallel with the CAMERA CHANNELS jacks on the continuous events side.

Programming of the patch panel is accomplished by connecting an EVENT OUTPUTS jack to a CAMERA CHANNELS jack with a patch cord. Channels can be used in parallel by patching the pairs of jacks in the CAMERA CHANNELS rectangles in a daisy-chain fashion.

(d) ECC Distributor Matrix Board

Before the ECC equipment can be employed, the matrix board must be programmed. This step is done by inserting skip pins into the holes on the matrix board. The matrix board contains three decks, each with 160 terminals (holes). Deck I is the mode II input deck with all terminals bused together, and deck 2 is the mode I input deck with all terminals bused together. Deck 3 is the output deck with all terminals isolated. The skip pins used to program the board are designed to connect deck I or deck 2 with a terminal on deck 3. To program the board for mode I operation, mode I pins are used. These pins contain insulating material at the point where they intersect deck 1, so that only deck 1 will be connected to a terminal on deck 3. Mode II pins have insulation which will isolate deck 2.

The matrix board is programmed by inserting mode I (black) pins into holes for channels selected for mode I operation, and mode II (white) pins into holes for channels selected for mode II operation.

 

(e) Mode Selection and Operation

The mode of operation for emergency control is determined at the ECC mode selector panel by setting the MODE I/MODE II switch to either MODE I or MODE II. With the switch in the MODE I position, the emergency cameras will run for 15 minutes, with the switch in MODE II position, the emergency cameras will run for 60 seconds. The cameras are turned on by closing the START/OFF switch on the ECC panel in one of the firing rooms.

(f) Modem Line Patch Panel

The line patch panel contains 64 jacks which are used to patch the output signals from system 1 or system 2 to the data modem at PTCR-A or PTCR-B. This panel must be patched to complete the loop for the control system. Patching is accomplished by connecting two-conductor shielded patch cords from the input system 1 or system 2 sequencer jackfields to the output [PAD A, PAD B, or Vehicle Assembly Building (VAB) interface] jackfields. These patches can be made in any combination provided that CONTROL jacks are patched together and STATUS jacks are patched together.

 

(g) PTCR Patch Panels

The PTCR-B output patch panel has status provisions and is used to patch starts. The PTCR-A patch distributor is used to patch starts and status. The PTCR-A output patch distributor is a 42-connector unshielded patch rack (5331A7). It is used to patch multiplexer starts and status to the perimeter sites, MLP, and the FSS. [Reference 79K07360, sheet 7, for the multiplexer channel circuit assignments ( 1 60-channel system capability) for the LC-39A pad, FSS, and MLP sites. Reference sheet 12 for the PTCR photo-optical cable interconnect system.]

 

(3) Multiplexing and Transmission

(a) Parallel-to-Serial Conversion

The signal which has been processed and conditioned as described previously is a dc level shift signal, 0 V dc being the ON condition and -6 V dc being the OFF condition. At point A in figure 150, there are 160 lines (channels) of control multiplexers. The control multiplexer performs the parallel-to-serial conversion. The bit rate control section of the multiplexer clocks the multiplexer logic at the rate of 2,000-pulses-per-second. To keep the system in synchronism, a 2.4 kpps timing signal from the data modems is applied through inverters to the clock purser inputs and to the divide-by-48 decimal counting unit (DCU) load command generator.

The divide-by-48 DCU load command generator counts continuously during multiplexer operation. When the [N99] DCU reaches the count of 48, it resets to zero, generates a load command, and applies the load command to the multiplexer shift register, which then directly resets the 48-bit shift register flipflops. After the shift register flip-flops have been reset, they are loaded simultaneously with the 7-bit frame reference word (1101010 or 0010101), 1-bit of loop check information, and 40 bits of camera control information. A1148 shift register flip-flops are clocked simultaneously by the shift clock pulses from the bit rate control logic. When the shift clock pulse goes positive, the information stored in each flip-flop is shifted out and into the succeeding flip-flop.

This procedure is accomplished by gating the true output of one flip-flop into the false input of the succeeding flipflop, and the false output of the second flip-flop into the true input of the third, etc. Finally, the information is shifted out of the register as binary ones and zeros represented by 0-V-dc and -6-Vdc levels, respectively. At this point, the control information is still in dc level shift form which is applied to the multiplexer output logic. The multiplexer output logic converts the dc level shift information into an RZ serial data train of ones and zeros represented by voltage levels of + 5 V dc and - 5 V dc, respectively, as shown in figure 151. The RZ serial data train is then filtered to 0 square off the pulse and eliminate transients.

 

(b) Demultiplexer

The control demultiplexers located at the PTCR's receive the outputs of the data modems and demultiplex them into parallel outputs (40 for each demultiplexer) which are used to drive relays in the camera control repeaters.

The serial pulse train from the data modems enters the demultiplexer control logic section which consists of zero and one threshold detectors, clock pulsers, load data flip-flops and associated gates, frame reference load command flip-flops, and activity sensors.

The threshold detector clock purser logic consists of two Schmitt trigger threshold detectors, a two-way OR gate, a clock purser, and three inverters. The positive-going serial data train from the data modems are converted into negative-going (0 to -6 V) pulses by the one threshold detector; at the same time, the negative-going pulses are converted to pulses of 0 to -6 V by the zero threshold detector. (The Schmitt trigger circuits square the pulses and increase their amplitude.) The threshold detector outputs are inverted and fed to the 56-bit shift register. The threshold detector outputs are fed to a two-way OR gate which generates clock pulses which clock the load data flip-flops.

 

(c) Frame Reference Comparator

The frame reference comparator samples the 56-bit shift register and extracts the frame reference information. If the comparator sees the frame reference word, 1101010, followed by 41 bits of camera control and loop check information, and then the complement of the frame reference work, 0010101, a load command will be generated and the loop check and camera control bits will be shifted out and stored in the 41-bit storage register. At the same time, the 56-bit shift register is primed for another sampling by the comparator. The trailing frame reference word in each case is also the leading frame reference word for the next frame. If the frame reference comparator does not detect a frame reference word which is always the complement of the preceding frame reference word, no load command will be generated and the demultiplexer will have no output. This ensures a high immunity to noise and a high degree of system security.

(d) Data Outputs

Once the frame reference has been verified and a load command has been generated by the frame reference comparator, the loop check bit and 40 bits of camera control information are shifted into the 41-bit storage register. The storage register outputs operate relay drivers which supply a ground to the relays in the camera control repeaters. The negative side of the mux/demux power supply (-28 V dc) is wired to one side of the CCR relays in parallel. When a given relay driver sees a binary one input from the 41-bit storage register, it saturates and causes a ground (0 V dc) to be applied to the CCR relay, causing it to energize. Conversely, if a zero is stored in the storage register, the relay in the CCR will see a high resistance and will not energize.

The signal has now been converted to parallel data by the demultiplexer so that the signal to point F in figure 150 is 40 lines of dc level shift information.

(4) Loop Check Operation

The loop check circuit provides a method of verifying that the mux/demux loop is in synchronism and transmitting information.

The control switch patch panel provides five pushbutton indicating switches (one for each mux/demux loop), which are used to activate the loop check circuit. When one of these switches is pressed, the eighth bite in the serial data train will be a binary one which will cause the appropriate flip-flop in the multiplexer shift register to have a true output. This output is connected to one input of an AND gate, the other input of which is the load command pulse. When both inputs are true, the AND gate will have an output and a binary one will be stored in the storage register to be transmitted through the loop to the demultiplexer; the loop check bit is ANDed with the -28 V dc from the demux/mux power supply; and, if both inputs are true, the demultiplexer output for the eighth bit will be an ON signal which is transmitted directly to the status multiplexer and finally back to the LCC demultiplexer. Here it is demultiplexer along with the 40 bits of status information and used to light the LOOP CHECK indicator on the control switch patch panel. If a LOOP CHECK lamp does not light when the switch is pressed, the associated mux/demux loop is not transmitting properly.

(5) Synchronization Detection and Indication

Each mux/demux and demux/mux unit has a SYNC indicator located on its front panel which serves to verify that the demultiplexer is in synchronism with its associated multiplexer. This is accomplished when the 2.4 kpps shift clock pulse in the demultiplexer bit rate control logic is sampled by an activity sensor for approximately the first 700 microseconds of each pulse, and the output of the load command generator is sampled by another activity sensor, for approximately 25 ms. When both of these outputs are true, a lamp driver is enabled and the indicator will light.

(6) Timing and Repeating Equipment

(a) CCR Operation

Each CCR channel receives, via the buffer relay panel, a control signal from the channel of the output logic of one of the control demultiplexers and -28 V dc power. The -28 V dc is applied to one side of the CCR relay in parallel. The control signals are applied to the other side of the relay (one control line for each relay). The -28 V dc is always present on one side of the relay as long as the system is energized. When the control demultiplexer channel output is in the off condition, the potential at the control input side of the relay is nearly -28 V dc so that essentially no potential difference exists across the relay, and current cannot flow. When the channel is turned on, the output circuit of the relay driver saturates and goes to 0 V, causing the relay to energize.

 

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[N100]

Figure 151. Multiplexer Shift Register and Logic Outputs.

Figure 152. Camera Locations and Look Angles.

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[N101] When the relay energizes, 120 V ac power is routed through the relay contacts through the camera service cable to the camera motor and the camera runs. At the same time, an enable signal (ground) is routed to the corresponding channel of the associated TTU. This enable signal causes the TTU LED driver to supply the selected timing code to the same camera.

(b) TTU Operation

The TTU receives IRIG-differentiated bipolar timing codes from the KSC timing system through the timing distributor and monitor panel and converts it to a dc level shift signal of sufficient amplitude to drive the timing LED in motion picture cameras. Each TTU operates in conjunction with one single-phase CCR or two three-phase CCR's supplying control and timing signals to 10 motion picture cameras. Each TTU channel is enabled by one CCR channel and the two companion channels are routed over the same cable to a single camera.

 

(c) Time Code Reconstruction

The TTU contains a bipolar level shift converter which accepts IRIG bipolar signals with a minimum amplitude of 2 V base-to-peak. At present, the time codes used are IRIG-A, IRIG-B, IRIG-E, and IRIG-H. The bipolar signals are applied to Schmitt trigger circuits which produce dc level shift pulse trains (O to -6 V dc) which follow (track) the input pulses. The outputs of the bipolar level shift converter are applied to AND gates on LED driver cards (one for each channel). The other input to these AND gates is the enable signal from the CCR. When the two signals appear at the AND gate simultaneously, the AND gate is turned on and the LED in the camera glows. When the bipolar level shift converter output is at O V and the AND gate is turned off, the camera timing LED turns off. LED currents may be monitored at the LED monitor chassis on the TTU.

(7) Status Signals

(a) Generation of Status Signals

The CCR's are capable of generating status signals to be multiplexed and transmitted back to the LCC demultiplexers where they can be demultiplexed and routed to status lamps on the camera control panels. The equipment is designed to sense the presence of 120 V ac on the camera START relay contacts that supply voltage to the camera motor. This status multiplexer input results in an illumination of a "lighted" switch handle on the camera control panel (reference 79K07360, sheet 3).

(b) Master Status Switch

There are two master status switches, one for each photo-optical system. The master status switch, when in the TEST (up) position, will illuminate the channel selector switches which are patched to their respective multiplexers. Normal status is indicated with the switch in the down position.

(8) Backpatching the L CC mux/demux

The LCC mux/demux can be backpatched to check the operation of the LCC portion of the control and timing subsystem. Backpatching consists of disconnecting the cables from J 101 and J102 of each mux/demux, and then connecting J101 to J102 with a short piece of coaxial cable. The result is that the control multiplexer output is fed directly to the status demultiplexer input and the loop is closed. In this configuration, each camera control channel which is turned on (either automatically or manually) will produce a control multiplexer output. Since the control multiplexer is patched directly to the status demultiplexer input, the status demultiplexer will produce an output which will cause the corresponding status lamp in the switch handle on the camera control panel to light.

(9) Camera Control Sequencer

Start, hold, and hold-inhibit signals can be provided to operate the camera control sequencer locally from LCC room I P9. The sequencer is normally preset to a preselected count before beginning a sequence. When this count occurs, the launch sequence start switch is closed, starting the sequence counter. If while the counter is running, a hold signal (closure) is received, the counter stops. During a launch countdown, the launch processing system will provide the start and stop signals, but not hold inhibit.

(10) Hold Inhibit

The camera control sequencer has hold-inhibit circuits which are used to inhibit any hold signals from LPS during critical intervals of the countdown. If a hold were allowed to stop the sequencer at certain times, film breakage and camera damage could result when certain cameras are stopped and restarted (discontinuous events cameras). Also, a hold of too long a duration could cause film runout (on continuous events cameras) and possible damage to camera motors. Sequencer circuitry permits a hold inhibit to be generated automatically by the sequencer. However, it is planned that the hold inhibit signal be generated internally by the camera control sequencer at a preprogrammed time. When the hold inhibit signal is present, the counter will continue to run in the presence of a hold command. When a holdinhibit term is generated, its associated lamp driver will supply a ground to the appropriate indicator on the sequencer front panel. With the term not present, the lamp will extinguish.

c. Other Equipment.

(1) Sequencer Synchronization Control Panel

System 1 and system 2 can be operated independently or simultaneously. The sequencer control panel provides a switching arrangement whereby the launch start and hold signals can be switched from any of four common data buses to either sequencer. Simultaneous synchronized operation is accomplished by setting both switches (system 1 and system 2 sequencers) to operate from the same common data buffer bus.

(2) ECC FR Selector Panel

The ECC firing room selector panel enables the ECC subsystem of system 1 or system 2 to be operated from either of the two firing rooms.

(3) Sequencer Power Supply Monitor Panel

The sequencer power supply monitor panel in rack E 14 is provided to monitor the voltage outputs of the dual power supply in the pad A sequencer.

d. Operation and Maintenance

For further information on the operation and maintenance of this system, refer to Operation and Maintenance and Specifications Document 79K14913.

e. Shuttle Photographic Tracking Coverage

Photographic coverage of the Shuttle launch vehicle has been implemented per requirements in the Program Requirements Document (PRD) and supported per the Photographic Acquisition-Disposition Document (PA-DD) by the photographic contractor.

Coverage is provided from prior to ignition until after SRB separation or until limit of visibility. Location of various cameras discussed in this subsection are shown in figure 152.

This sequence of coverage starts with a remote-controlled tracking mount on the east side of the launch complex that provides three 16mm overlapping views of the vehicle from T minus 12 seconds through lift-off and a committed altitude of 1200 feet. This mount, under normal conditions, usually tracks well beyond the commitment and is controlled from the Launch Control Center.

Also, at ignition, cameras are started at three off-complex intermediate focal length optical tracker tracking mounts. These mounts are located at universal camera sites that are north, west, and south of the launch pad at a distance of 3 to 7 miles. Each of these mounts has a 16mm and a 70mm camera for coverage of early flight. Although they do provide coverage at lift-off, the lenses are not in proper focus and are not committed until the vehicle has reached an altitude of approximately 1200 feet. These cameras provide coverage until augmented by long-range instruments. One mount, in addition to the above three mounts, is normally located within 3 miles southeast of the pad. This [N102] mount provides 70mm coverage of lift-off through rollover. This mount is primarily a platform for a broadcast-release television camera.

The long-range tracking instruments (mounts) are either mobile trailers or stationary units. They are manual or computer-assisted and are linked to the Eastern test range radar and range computer.

They are identified by type of mount:

MIGOR - Mobile intercept ground optical recorder It ground optical recorder

ROTI - Recording optical tracking instrument

These instruments utilize 35mm or 70mm cameras coupled to lenses with focal lengths ranging from 100 inches to 500 inches. These lenses are auto-focus and temperature compensated.

Coverage by these instruments is from first acquisition until LOV. Two mounts are located north and two mounts are located south of the flight line at a distance of 6 to 40 miles. Two of these mounts (one north and one south) are planned to track the Orbiter through and after SRB separation. The other two mounts will follow the launch vehicle until SRB separation and then track SRB entry to LOV.

All of the above cameras, mounts, and instruments are dedicated to requirements of viewing structural integrity, propulsion performance, and possible flight anomalies of the launch vehicle. These data are committed only during daylight hours (sunrise plus 45 minutes, sunset minus 45 minutes).

In the event of a launch being scheduled beyond this daylight period, exposure will be adjusted to "flame exposure" providing coverage of the plumes.

In addition, all tracking coverage is contingent upon weather conditions and cloud coverage at time of launch.