Serial Connector Pin Assignments
The SyncLink PCIe card has two high density 26 pin D-SUB male connectors (HD-26), one for each port.
The HD-26 connectors allow two ports to fit on a PCIe bracket. Adapter cables included with the card
convert the HD-26 to the larger standard DB-25 male connector. Each port is configured for a specific
serial interface standard as described in the
Serial Interface and Termination Selection
types that use a connector different than DB-25 (V.35, RS-449, X.21) require an additional adapter cable
to convert the DB-25 to the required connector type. The following sections describe the cable pin
assignments for supported standards.
RS-232
RS-232 defines single ended signals on a DB-25 connector. Use a straight through 25 conductor DB-25M
to DB-25F cable, such as MicroGate Part # CMF000.
Maximum data rate is 128Kbps. Cable length and signal loading may reduce the maximum data rate.
RS-232 DB-25 Male DTE
Signal
Electrical
HD-26 Pin
DB-25 Pin
Direction
TxD, Transmit Data
RS-232/V.28
8
2
Output
RxD, Receive Data
RS-232/V.28
17
3
Input
RTS, Request to Send
RS-232/V.28
1
4
Output
CTS, Clear to Send
RS-232/V.28
24
5
Input
DSR, Data Set Ready
RS-232/V.28
19
6
Input
Signal Ground
14
7
DCD, Data Carrier Detect
RS-232/V.28
22
8
Input
TxC, Transmit Clock
RS-232/V.28
25
15
Input
RxC, Receive Clock
RS-232/V.28
10
17
Input
LL, Local Loopback Control
RS-232/V.28
13
18
Output
DTR, Data Terminal Ready
RS-232/V.28
3
20
Output
RL, Remote Loopback Control
RS-232/V.28
12
21
Output
RI, Ring Indicator
RS-232/V.28
20
22
Input
AuxClk, DTE Clock Output
RS-232/V.28
6
24
Output
RS-232 Cable (Part# CMF000)
