Sheet 1

This sheet gives an overall idea of how the ADC prism cell stage is interconnected and of the various components used. The lines show, through the use of arrow heads, the direction of signal flow. Note that in some cases the signal path is bi-directional. Note also that the AC power wiring is denoted by using double lines. The AC power for the stage components come from the Pulizzi power controller channels 1, 2, 3 and 4. The power controller provides a means for the software to control the power sequencing when bringing the system up or taking it down. In the current version of the software, the default power up sequence is used. This sequence goes as follows: the power controller turns on, after about 1 second the first outlet comes on, after another second the second outlet comes on, and so on.
The servo motor supply supplies the 24V DC power for the Galil servomotor power amplifier and the control voltage for the various interlock relays on the Limit Interlock panel (EL-3612). The Galil AMP-19520 connects to the Galil controller via a 100-pin cable. The controller supplies the drive signals to the amplifier and receives position information from the motor encoder via the amplifier module. The auxiliary encoder is also wired through the amplifier module. A special cable (of which a spare is provided) has been built to connect the auxiliary encoder signals to the DMC-2210. This was needed because the 100-pin main interconnect cable between the controller and amplifier does not include this wiring. The normal path for these signals would have been to connect a High-Density 36-pin cable to a break-out board and then wire to the DB25 connector on the amplifier. This would have required the mounting of another board and the use of 1 meter cables for both the controller cable and the amplifier cable. Instead, a one meter long 36-pin High-Density cable was purchased and cut in half and the needed wires were terminated into the required DB25 connector. (See EL-3614 sheet 2 for wiring details)
The stage limits consist of software, primary limits, and secondary limits. If the stage is run into any of these limits, the motion restrictions become increasingly severe. First off, the software limits, once tripped, will allow the motor to decelerate to a controlled stop. The controller will be able to back the stage out of this kind of a limit but will not be able to proceed further into the limit. As a backup to these limit, the primary limits are set to actuate if the stage has somehow been able to exceed the software limit. They provide the same function in that the stage can be commanded to reverse out of the limit but again, can't proceed further into the limit. The secondary limit provide the last protection against possible damage to the stage. Once a secondary limit is encountered, the motor power is cut off to the stage. There is no deceleration provision. If the stage moves into this limit, the stage will have to be moved out of the limit by hand. Again, this is an extreme state for the stage to be in. It means that the stage has progress through both the software and primary limits to make it to this point. A special condition can exist that will allow a retract motion. This is meant as a way to allow the stage to be brought to the null position. This requires that the operator manually turn a switch on the front of the electronics box to put the system in bypass mode. Once in bypass mode the electronics will apply a -15V level to the motor. This will run the stage to the null position if there no retract limit are in force. Once the stage retracts, the operator should power down the control box and run the rest of the night without the ADC. In the morning the observatory electronics staff should troubleshoot and correct any problems.

Sheet 2

This sheet shows the more detailed wiring of the Galil AMP-19520 servo amplifier. To the left side of the drawing, the connections between the DMC-2210 and the AMP-19520 are shown. Oddly enough, the Galil equipment does not number many of their connectors. Instead, they give most, but not all, of them descriptive names! On the DMC-2210, the connector named 'AXES A-D' is the main logic cable and it connects to the AMP-19520's J1 connector. The next cable is the special made cable that connects the auxiliary encoder and is labeled 'AUX ENCODER' at both ends. (See description in above section). Below the DMC-2210 block is the Lambda JWS-150/24A +24V power supply that supplies the motor and relay power for the system. The +24V DC is wired into the amplifier via the 'DC POWER IN' connector and into the interlock panel via J402. Note that there is a blue/black twisted pair of wires that run from the power supply to J4 of the Temperature Sensor board. This is the monitor signal that allows the software know what the voltage is of the supply.
On the right side of the amplifier block are the motor output, labeled MX, the stage limit connector, labeled AUX I/O J3, the axis encoder connector, labeled X, and the analog connector labeled ANALOG. The block in the upper center of the drawing represents the Interlock panel. At the top, J402 is a 3-pin connector that wires the +24V supply to the interlocks. This is used for the relays and as a supply for most of the front panel indicator LEDs. On the left side is the motor power connector. Note that pins C and D are tied together. This is the continuity line for the motor cable MOTOR_CONN signal. Because there is no provision for such a signal at the amplifier, this is as close as the signal makes it to the amplifier. This points out that if the connector is disconnected at the amplifier, there will be no feedback of that fact to the software. On the other hand, if any of the other connectors to the motor are disconnected, the software will know via the MOTOR_CONN signal. J404 on the right side of the block shows the motor wiring leaving the interlock panel. On the bottom of the interlock block shows the stage signals coming in from the stage via J406 and exiting the panel via J405. These are the limit and home signals associated with the stage and, with the exception of the HOME signal, all control relays via the Relay Driver board. The signals that are then are sent out via J405 are derived from contacts on these relays.
Back at the amplifier block, The encoder connections represent both the motor and load encoder wiring At the bottom, center of the page is the connection to the Temperature Sensor board. This board provides connection points and buffering for up to three LM35 solid-state temperature sensors and an input for monitoring the +24V power supply. In this application, only the onboard temperature sensor and the 24V monitor channels are used. If wanted, two more temperature sensors could be added and connected via the two unused DB9 connectors on the board.
The blocks labeled J301 and J302 represent the two front panel connectors on the electronics box.

Sheet 3

This sheet shows the I/O wiring within the ADC electronics cabinet. The IOM-1964 I/O panel is mounted to an aluminum plate to make it modular. All signals coming into or out of the IOM are wired to one of three connectors. The signal cable to the Galil controller connects directly to the IOM vi its J1 80-pin connector. The aluminum panel has two connectors. J701 is a DB25 connector and it receives signals that come directly from the stage. J702 is a High-Density DB15 connector and it receives the signals generated in or associated with the interlock system.
Signals on J701 include:

• AFT_RET_2ND is the aft prism cell's retract secondary limit signal.
• AFT_DPL_2ND is the aft prism cell's deploy secondary limit signal
• AFT_HOME is the aft prism cell's home signal.
• MOTOR_ENCD_CONN is the continuity signal that tells the controller that the motor encoder is connected to the system.
• LOAD_ENCD_CONN is the continuity signal that tells the controller that the secondary, or load, encoder is connected to the system.
• FWD_CELL_CONN is the continuity signal that tells the controller that the forward prism cell limits are connected to the system.
• AFT_CELL_CONN is the continuity signal that tells the controller that the aft prism cell limits are connected to the system.
• MAIN_CABLE_CONN is the continuity signal that tells the controller that the overall logic cable is connected to the system.

Signals on J701 include:

• 2RET is the forward prism cell secondary retract limit signal.
• 2DPL is the forward prism cell secondary deploy limit signal.
• MOTOR_CONN is the continuity signal that tells the controller that the motor power cable is connected to the system.
• MAN_PADDLE_CONN is the continuity signal that tells the controller that the manual paddle has been connected to the system.

The LIMIT INTERLOCK PANEL block shows the connections important to the interlocks that wire from the panel to the rest of the I/O. J403 and J404 pins 'C' and 'D' show the interconnect path of the MOTOR_CONN signal. J405 shows the connections for the MOTOR_CONN signal and the forward prism cell secondary limits. The secondary limit signals are derived from relay contacts on the interlock panel. J406 shows the signal wiring from the actual Hall-effect sensors to the interlock panel. Notice that the signal V_LIMIT is passed from the interlock panel to the prism stages. This signal is normally the +5V supply from the Galil DMC-2210 controller. However, if the reason for a failure is due to a failure of the units 5 volt supply, by invoking the Bypass system, that line is connected to the +15V bypass power supply. This allows the Bypass action to take place even if such a failure occurs. The Bypass system will run the prisms to the null position.

J202 is the manual paddle connector. The manual paddle allows the operator to move the stage without the need of having to use the GUI. The DEPLOY_A, DEPLOY_B, RETRACT_A, and RETRACT_B signals are derived from the deploy and retract buttons on the manual paddle. They control the motion of the stage and interlock themselves via the wiring of the switches. MAN_PADDLE_CONN is the continuity signal that tells the controller that the manual paddle has been connected to the system. The LOCAL/REMOTE signal tells the controller the status of the paddle and changes the state of the LOCAL relay R7 which directs the current for the motor from either the amplifier or the PWM board on the interconnect panel.

J301 and J302 are the connectors on the output panel of the electronics cabinet.

Sheet 4

This sheet shows the wiring of the stage motor, motor encoder, and the load encoder. At the top, left of the drawing the motor power comes in on J601. Notice that pins C and D are shorted together. This provides the continuity for the MOTOR_CONN signal by tying the MOTOR_CONN signal to GND. Thus, if the connector is not attached the control software will know that it can't move the stage and will pass that information on to the user GUI. The motor encoder is connected to J602 and the load encoder is connected to J603. Notice that each of these connectors shorts out a CONNected signal to GND and that they are on different pins of the encoder connectors. In this case not only does the signal tell if the connector is in place but it also discriminates between the two encoders.

Sheet 5

This sheet shows the wiring for the forward and aft prism cell limits. J604 at the top shows the forward prism cell wiring. Pin A brings the V_LIMIT level to the Hall-effect sensors. Recall that the V_LIMIT level is +5V during operation and +15V during bypass operation. Pins B and J are grounds. Pin C is the forward cell deploy secondary limit signal. Pin D is the forward cell deploy primary limit signal. Pin E is the forward prism cell HOME signal. Pin F is the forward cell retract secondary limit signal. Pin G is the forward cell retract primary limit signal. Lastly, Pin H is the FWD_LIM_CONN, or forward prism cell limit switch connected signal. It is tied to GND when the connector is connected. The dotted lines group together the sensors that are mounted on each sensor board. In the case of the forward prism cell, the primary and secondary limits and the HOME signal sensors are mounted on one circuit board. Looking at the board you will notice that two of the sensors are vertically aligned with each other and the third, or middle, sensor is at a different height. When viewed from the opposite side of the instrument the sensors are identified as follows:

• The right most sensor is the home position sensor. If the prism cells are moving from the retracted position to the deployed position, this is the first sensor to be blocked by the vane attached to the forward cell. This is the longer of the two vanes.
• The center sensor is the primary limit switch. It is actuated by the shorter of the two vanes.
• The sensor on the end furthest from the retracted position is the secondary.

Note that even though the primary and secondary limit sensors appear to be a long way from each other, the vanes that actuate them are different sizes. Thus, the difference in trip points is about one and a half millimeters.
The lower of the two circuits on the schematic show the forward prism cell retract primary and secondary limit sensors. These two work in exactly the same way as the deploy limits. The upper vane acuates the primary limit and the lower vane actuates the secondary limit. Again, the spacing between the two is about one and a half millimeters.

J605 at the right shows the aft prism cell wiring. Pin A brings the +5V supply to the Hall-effect sensors. Pins B and J are grounds. Pin C is the aft prism cell deploy secondary limit signal. Pin E is the aft prism cell HOME signal. Pin F is the aft prism celll retract secondary limit signal. Lastly, Pin H is the AFT_LIM_CONN, or aft prism cell limit switch connected signal. It is tied to GND when the connector is connected. As above, the dotted lines group together the sensors that are mounted on each sensor board. Note that the aft cell does not have primary limit switches. Because a stage can have only one set of primary limits, these would be ambiguous if used. Also, the secondary limits and the aft HOME signals are meant only as 'sanity check' inputs. That is, when the forward cell is in a limit or at the home position, the aft cell signals should agree.

Sheet 6

This sheet shows the the wiring for the manual paddle. The +24V power line is wired from Pin A to one pole of the SPDT LOCAL/REMOTE switch. When the switch is set to remote, or computer control the +24V is disconnected from the direction pushbuttons. At that same time the LOCAL/REMOTE signal is tied to ground via the second pole of the switch. This line is wired to one side of the relay coil of RLY7, the LOCAL relay,and the other side of the coil is wired to GND. thus, the relay is not energized. Also at this time, the normaly closed pole of both direction switches are tied to GND. Because the normaly open poles of the direction switches are also wired to GND, there can be no energizing of either direction relay. (On the interlock panel these are relays MDPL and MRET - for manual deploy and manual retract).
When the switch is moved to the LOCAL position, Pin G is connected to +24V which pulls in the LOCAL relay in. It also connects the normaly closed contacts of the direction switches to +24V. Now with the +24V available to either switch, pushing either switch will pull in the appropirate direction relay. A direction interlock is achieved by wiring the GND for each relay through the normaly closed contact of the opposite direction switch. Thus, if you push and hold one direction button and then push the other, the GND signal is removed from both direction relays. As will be seen in the Interlocks write-up, each direction relay coil is wired through the primary limit relay for that direction.