APC UPS control system - Manual (Page 154)

action = ioctl(TIOMCBIS, DTR) set DTR (kills power)
RS232 Wiring and Signal Conventions
DB-25 Pin # DB-9 Pin # Name DTE-DCE Description
1 — FG – Frame Ground/Chassis GND
2 3 TD –> Transmitted Data, TxD
3 2 RD
<
– Received Data, RxD
4 7 RTS –> Request To Send
5 8 CTS < – Clear To Send
6 6 DSR < – Data Set Ready
7 5 SG –— Signal Ground, GND
8 1 DCD < – Data Carrier Detect
9 — — – Positive DC test voltage
10 — — – Negative DC test voltage
11 — QM
<
– Equalizer mode
12 — SDCD
<
– Secondary Data Carrier Detect
13 — SCTS < – Secondary Clear To Send
14 — STD –> Secondary Transmitted Data
15 — TC < – Transmitter (signal) Clock
16 — SRD
<
– Secondary Receiver Clock
17 — RC –> Receiver (signal) Clock
18 — DCR
<
– Divided Clock Receiver
19 — SRTS –> Secondary Request To Send
20 4 DTR –> Data Terminal Ready
21 — SQ
<
– Signal Quality Detect
22 9 RI < – Ring Indicator
23 — — –> Data rate selector
24 — — < – Data rate selector
25 — TC
<
– Transmitted Clock
Pin Assignment for the Serial Port (RS-232C), 25-pin and
9-pin, Female End
13 1 5 1
_______________________________ _______________
\ . . . . . . . . . . . . . / \ . . . . . / RS232-connectors
\ . . . . . . . . . . . . / \ . . . . / looking into the
--------------------------- ----------- end of the cable.
25 14 9 6
153