System control is implemented using a microprocessor and a Field-programmable Gate Array (FPGA).
Volatile Program/Data Memory
SDRAM memory is provided for program data storage and program execution space for the Motorola PPC.
Multidrop Bus
The APC2 Board provides serial data over the UPS1200 Multidrop Bus. The APC2 Board receives status information from other boards on the bus and sends commands to the other boards on the bus.
The APC2 Board has a jumper-selectable 100 Ohm terminating resistor for the Multidrop bus. Jumper "JMP9" provides terminal resistance. Set the APC2 Board terminating resistor jumper to the setting on the following table.
| APC2 Settings | |
|---|---|
| Terminating Resistor | "JMP9" - Never installed |
Refer to Systems Operation, Testing and Adjusting, RENR7654, "Multidrop Network - Setup" for information on setting up the Multidrop Network.
Battery
The battery ("B1") should be replaced every 5 years using the procedure that is found in the following section: Systems Operation, Testing and Adjusting, Troubleshooting, RENR7654, "Personal Computer to UPS Connection".
Removal
- Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Controls Cabinet)" in order to de-energize the system and gain access to internal components.
- Disconnect all connectors from the board.
The connectors locations in the unit are labeled. Verify each connector to make sure that the label is present and legible.
Refer to Illustration 1.
 | |
| Illustration 1 | g01278526 |
| NOTICE |
|---|
Electrostatic discharge can damage integrated circuits or semiconductors if you touch bus connector pins. When not in use, keep the module in the static-shield bag. Follow these guidelines when you handle any module: Touch a grounded object to discharge static potential. Wear an approved wrist-strap grounding device. Do not touch the bus connector or connector pins. Do not touch circuit components inside the module. If available, use a static-safe work station. |
- Remove the cross head ground screw, labeled "J25", from the bottom right of the board.
- Disconnect the seven white plastic stand-offs connecting the board to the left panel using the following method.
Note: The board must be removed from the stand-offs without bending the board.
- Pinch the head of each stand-off so that the board is not locked to the stand-off but is still attached to the stand-off.
- Remove the board by gently and evenly pulling the board from all stand-offs at the same time.
Installation
| NOTICE |
|---|
Electrostatic discharge can damage integrated circuits or semiconductors if you touch bus connector pins. When not in use, keep the module in the static-shield bag. Follow these guidelines when you handle any module: Touch a grounded object to discharge static potential. Wear an approved wrist-strap grounding device. Do not touch the bus connector or connector pins. Do not touch circuit components inside the module. If available, use a static-safe work station. |
- Position the board in the cabinet over the seven white stand-offs that are connected to the left panel.
- Push the board, gently and evenly, onto all the stand-offs simultaneously. Make sure all stand-offs are locked in place.
- Attach the cross head ground screw into the bottom right hole of the board labeled "J25".
- Plug the wire connectors into the correct connectors on the board. Check the labels on each connector for proper placement. Refer to Illustration 1.
- Calibrate the APC2 Board.
Refer to the information in "Calibrations".
Calibrations
The following calibrations must be performed whenever the APC2 Board is replaced:
- Systems Operation, Testing and Adjusting, RENR7654, "DC Bus Voltage - Calibrate"
- Systems Operation, Testing and Adjusting, RENR7654, "AC Voltage - Calibrate"
- Systems Operation, Testing and Adjusting, RENR7654, "In Current - Calibrate"
- Systems Operation, Testing and Adjusting, RENR7654, "AC Output Current - Calibrate"