GAI-Tronics ACC2500 Audio Control Center - Manual (Page 32)

Installation ACC2500 Audio Control Center
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PB3 – Internal Diagnostics
There are four internal diagnostic modes available; dc or MLS module, depending on the board installed
(PB1), relay module (PB2), RS-232 (PB3), and keyboard (PB4). After the internal diagnostic mode has
been entered, they are accessed using the programming buttons as follows:
PB1 – Relay Module Diagnostics
This function is accessible via Main Diagnostics, then Internal Diagnostics ( PB3 ). The Model XRC0001A
Relay Option Kit must be installed in the unit under test. This function allows the relay I/O module to be
exercised. The display indicates the status of:
• Inputs – IN
• Relay – OUT
By pressing any key (except TRANSMIT ) starting at relay1 and progressing up to relay 4, the relays close
and then open. The numeral 1 in the OUT position indicates the relay should be closed. LEDs on the relay
I/O module also indicate the status of each relay.
To exercise the inputs, each input can be grounded. This is indicated by a numeral 1 in the IN position
associated with the input. As each input is shorted to ground, the corresponding 1 in the IN position
indicates a 0. To exit the relay module diagnostics, press
TRANSMIT .
PB2 – Toggle Backup Mode
The ACC2500 supports hot-standby mode. In order to unitize this feature, the primary unit must include
XRC0001A Relay Option and be connected properly.
When operating in primary mode, the unit engages relay 1 of the relay option board. This connects the RS-
232 data from the AMI directly to the primary unit. When power to the primary unit is lost, the RS-232
connection will be made to the backup unit which will then assume full command of the AMI. Additional
backup units can be cascaded in the same manner. When the primary ACC2500 recovers, it will take over
command of the AMI and the backup units will enter backup mode.
Upon entry to this diagnostic, the unit will toggle primary/backup operation. The display will indicate the
backup mode setting. Repeated selection of PB2 during internal diagnostics will, in-turn, enable and
disable backup operation.
Pressing any key while the display is indicating the backup mode setting will return to internal diagnostics.
PB3 – RS-232 Diagnostic
This function is accessible via Main Diagnostics, then Internal Diagnostics ( PB3 ), and exercises the RS-
232 port TX and RX data. To run this test, disconnect anything connected to the programming connector
on the back of the unit, and short pins 2 and 7 of the connector.
Once the short is completed, this unit sends data on the TX wire for receipt on the RX wire. If the same
data is received on the RX wire, the unit continues to send data. If no data, or incorrect data is received,
the unit stops sending data and displays failure.
Note that this diagnostic does not guarantee standard RS-232 levels. If the diagnostic functions, but the
unit does not operate with a PC or printer, verify with an oscilloscope that the proper RS-232 levels are
present. Press the
TRANSMIT button to exit the RS-232 diagnostic.