GE MDS SD Series Technical Manual page 34

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Table 8. COM2 Pin Descriptions—Radio in RS-232 Mode
Pin Radio
Number Input/ Pin Description
Output
1 OUT DCD (Data Carrier Detect/Link)—A high indicates signal
received.
2 OUT RXD (Received Data)—Supplies received data to the
connected device.
3 IN TXD (Transmitted Data)—Accepts TX data from the
connected device.
4 IN Sleep Mode Input—Grounding this pin places the radio in a
low power consumption mode.
5 -- Signal Ground—Connects to ground (negative supply
potential) on chassis.
6 OUT Alarm Output (DSR)—Behavior is user-configurable. Default
behavior: An RS-232 high/space (+5.0 Vdc) on this pin
indicates an alarm condition. An RS-232 low/mark (–5.0 Vdc)
indicates normal operation.
7 IN RTS (Request-to-Send)—Keys the transmitter.
8 OUT CTS (Clear-to-Send)—Goes "high" after the programmed
CTS delay time has elapsed (DCE), or keys another
connected radio when RF data arrives (CTS KEY).
9 -- Reserved—User I/O for special applications
Table 9. COM2 Pin Descriptions—Radio in RS-485 Mode
Pin Input/
Number Output Pin Description
1 OUT Carrier Detect/Link—A high indicates signal received.
2 OUT TXD-/TXA (Transmitted Data -)—Inverting driver output.
Supplies received payload data to the connected device.
3 IN RXD-/RXA (Received Data -)—Inverting receiver input.
Accepts payload data from the connected device.
4 IN Sleep Mode Input—Grounding this pin places the radio in a
low power consumption mode.
5 -- Ground—Connects to ground (negative supply potential) on
the radio's PC board.
6 OUT Alarm Output—Behavior is user-configurable. Default
behavior: A high on this pin indicates an alarm condition; a low
indicates normal operation.
7 IN RXD+/RXB (Received Data +)— Non-inverting receiver input
8 OUT TXD+/TXB (Transmitted Data +)—Non-inverting driver output.
9 -- Reserved—User I/O for special applications
SD Series Technical Manual MDS 05-4846A01, Rev. H