Comtech EF Data SFC4200 - Manual (Page 52)

Electrical Interfaces SFC4200/SFC1275G Synthesized Frequency Downconverter
5-2 TM054 - Rev. 4.0
the individual online converters or the backup unit. This interface finds use in both the 1:1 and
1:N configuration type switches. The pinouts of the switch is listed in Table 5-1.
Table 5-1. J5 – Backup Switch Interface – D Sub 15-Pin Connector
Pin No. Signal Description
Controller
AS/3048 (J7)
1 N.O. Form-C contact summary fault
normally open contact 1
5 N.C. Form-C contact summary fault
normally closed contact 9
9 COM Form-C contact summary fault
common contact 2
13 GND Ground 10
2 +15 V Or’d Diode Or’d +15 VDC from
converter 3
6 FCB1 Fault Code Bit 1 11
10 FCB2 Fault Code Bit 2 4
14 FCB3 Fault Code Bit 3 12
3 FCB4 Fault Code Bit 4 5
7 IDB1 ID Bit 1 13
11 IDB2 ID Bit 2 6
15 IDB3 ID Bit 3 14
4 IDB4 ID Bit 4 7
8 INT O Interrupt 15
12 RMT 8
5.7 Equipment RS-485 (J6)
The Equipment Multi-Drop, Full-Duplex, Bi-directional RS-485 Interface (J6) allows
communication between converters. Because the RS-485 Interface uses a master/slave
(talker/listener) configuration, the converter that is designated as the backup will automatically be
established as the master. Under normal RS-485 protocol, the master will poll a specific slave
by address and only then will the slave unit respond. The swapping of Transmit Data and
Receive Data is accomplished in the inter-converter cable, as the hardware interface is identical
for all converters. Refer to Table 5-2 for pinouts.