Comtech EF Data SNM-1000 - Manual (Page 37)

SNM-1000 Node Control Modem Revision 3
Installation MN/SNM1000.IOM
2–5
2.3.1 EFBUS1/2 Port (J6)
The EFBUS port provides two separate 2-wire EIA-485 interfaces wired to a common
9-pin D female connector located on the rear of the MIDAS Node Control Modem.
The
IF Modulator and IF Demodulator status is also presented for external use.
The Modem Control serial port, EFBUS1, is used for control of other Comtech EF Data
traffic modems.
The signals are described in the following table, with signal names
having the MC prefix. The interface is ASYNC, EIA-485/2 wire, and 19.2 kbps.
The EFBUS2 port is reserved for communication with future MIDAS traffic modems.
Signal Function
Name
I/O
MIDAS
Conn Pin #
Signal
Level
Ground MCGND - 1 -
Demodulator fault BP_DF I/O 2 TTL
Modulator fault BP_MF I/O 3 TTL
Receive/Transmit + MS_RD/SD+(EFBUS2) I/O 4 EIA-485
Receive/Transmit - MS_RD/SD-(EFBUS2) I/O 5 EIA-485
Receive/Transmit+ MC_RD/SD+(EFBUS1) I/O 6 EIA-485
Receive/Transmit- MC_RD/SD-(EFBUS1) I/O 7 EIA-485
Ground MSGND - 8 -
Not used - - 9 -
Not used - - - -