GE MDS SD4A Technical Manual page 33

MDS 05-4846A01, Rev. F
Table 8. COM2 Pin Descriptions—Radio in RS-232
Pin Radio
Number Input/ Pin Description
Output
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-422/485 Mode
Pin Radio
Number Input/
Pin Description
Output
Carrier Detect/Link—A low indicates signal received.
1 OUT
2 OUT TXD+/TXA (Received Data +)—Non-inverting driver output.
Supplies received payload data to the connected device.
3 IN RXD+/RXA (Transmitted Data +)— (Transmitted Data +).
Non-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.
Alarm Output—Behavior is user-configurable. Default
6 OUT
behavior: A high on this pin indicates an alarm condition; a low
indicates normal operation.
7 IN RXD-/RXB (Transmitted Data -)— Inverting receiver input
8 OUT TXD-/TXB (Received Data -)—Inverting driver output.
9 -- Reserved—User I/O for special applications
COM2 PORT NOTES & WIRING ARRANGEMENTS:
• RXD+ / RXA and RXD– / RXB are data sent into the radio to be transmitted out
• RXD+ / RXA is positive with respect to RXD– / RXB when the line input is a "0"
• TXD+ / TXA and TXD– / TXB are data received by the radio and sent out
• TXD+ / TXA is positive with respect to the TXD– / TXB when the line output is a "0"
EIA-422 4-WIRE CONNECTIONS
TXD +
2
3
RXD +
RXD – 7
8
TXD –
Figure 20. RS-422/485 Wiring Arrangements
SD Series Technical Manual
Invisible place holder
EIA-485 2-WIRE CONNECTIONS
RXD + TXD +
RXD – RXD +
TXD + RXD –
TXD – TXD –
This jumpering must be provided by user.
2
RXD+/TXD+
3
7
RXD–/TXD–
8
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