STI Engineering rfi-9256, User Manual

Page: 60 / 109

Appendix A Technical Specifications
RFI-9256 Radio Modem User Manual Page 60 of 109
A.3 Connector Pin Assignments
DB25 Pin IDC Pin Function Comment
1 1 +12VDC
2 3 RxD (Main Port) Output (RS-232)
3 5 TxD (Main Port) Input (RS-232)
4 7 RxD (Auxiliary Port) Output (RS-232)
5 9 TxD (Auxiliary Port) Input (RS-232)
6 11 I/O Bit 7 Input/Output (CMOS)
2
7 13 I/O Bit 5 Input/Output (CMOS)
2
8 15 I/O Bit 0 Input/Output (CMOS)
2
9 17 I/O Bit 2 Input/Output (CMOS)
2
10 19 Synchronisation I/O
Input/Output (TTL). 100K pull-up, internal voltage
limiting.
11 21 NC
12 23 NC
13 25 GND
14 2 +12VDC
15 4 CTS (Main Port) Output (RS-232)
16 6 RTS (Main Port) Input (RS-232)
17 8 DCD (Main Port) Output (RS-232)
18 10 DTR (Main Port) Input (RS-232)
19 12 I/O Bit 6 Input/Output (CMOS)
2
20 14 I/O Bit 4 Input/Output (CMOS)
2
21 16 I/O Bit 1 Input/Output (CMOS)
2
22 18 I/O Bit 3 Input/Output (CMOS)
2
23 20 NC
24 22 NC
25 24 GND
–
26 GND
Table 19: RFI-9256 Interface Pin Assignments
2
Input/output with 10K

series limiting resistor. VCC=5V. Sink/source current limited to ±400uA.