Serial Interface/Cable Pinouts
RS-232

The RS-232 standard uses single ended signals on a DB-25 connector. The adapter DB-25 connector follows this standard when the port jumpers are installed for RS-232. Use any straight through 25 conductor DB-25M to DB-25F cable (such as MicroGate Part # CMF000) to connect the adapter connector to the communications equipment. The maximum data rate supported by the adapter when using RS-232 is 128Kbps. Cable length and signal loading may reduce the maximum usable data rate from this value.


RS-232 DB-25 Male DTE
Signal Name
Electrical Description
Pin #
Direction
Earth/Shield Ground
-
1
-
TxD, Transmit Data
RS-232/V.28
2
Output
RxD, Receive Data
RS-232/V.28
3
Input
RTS, Request To Send
RS-232/V.28
4
Output
CTS, Clear To Send
RS-232/V.28
5
Input
DSR, Data Carrier Detect
RS-232/V.28
6
Input
Signal Ground
-
7
-
DCD, Data Carrier Detect
RS-232/V.28
8
Input
TxC, Transmit Clock
RS-232/V.28
15
Input
RxC, Receive Clock
RS-232/V.28
17
Input
LL, Local Loopback Control
RS-232/V.28
18
Output
DTR, Data Terminal Ready
RS-232/V.28
20
Output
RL, Remote Loopback Control
RS-232/V.25
21
Output
RI, Ring Indicator
RS-232/V.28
22
Input
AuxClk, DTE Clock Output
RS-232/V.28
24
Output

RS-232 Cable
Synchronous RS-232 Cable (PN:CMF000)


V.35

The V.35 standard uses a mix of single ended and differential signals on a 34 pin block connector. To use this standard, install the V.35 jumpers on the port and use the MicroGate V.35 cable (Part # 2534GT, picture shown below). Note that the LL, RL, and RI signals are available on the adapter’s DB-25 connector when the V.35 jumpers are installed, but are not available (NC = no connect) on the 34 pin block connector when using the V.35 cable. The maximum data rate supported by the adapter when using V.35 is 10Mbps. Cable length and signal loading may reduce the maximum usable data rate from this value.


V.35 Male DTE
Signal Name
Electrical Description
DB25 Pin #
V.35 Block Pin#
Direction
Earth/Shield Ground
-
1
A
-
TxD (+/A), Transmit Data
RS-422/V.11
2
P
Output
RxD (+/A), Receive Data
RS-422/V.11
3
R
Input
RTS, Request To Send
RS-232/V28
4
C
Output
CTS, Clear To Send
RS-232/V28
5
D
Input
DSR, Data Set Ready
RS-232/V28
6
E
Input
Signal Ground
-
7
B
-
DCD, Data Carrier Detect
RS-232/V28
8
F
Input
RxC (-/B), Receive Clock
RS-422/V.11
9
X
Input
AuxClk, DTE Clock Output
RS-422/V.11
24
24
Output
AuxClk (-/B), DTE Clock Output
RS-422/V.11
11
W
Output
TxC (-/B) Transmit Clock
RS-422/V.11
12
AA
Input
TxD (-B), Transmit Data
RS-422/V.11
14
S
Output
TxC (+/A), Transmit Data
RS-422/V.11
15
Y
Input
RxD (-/B), Receive Data
RS-422/V.11
16
T
Input
RxC (+/A), Receive Clock
RS-422/V.11
17
V
Input
LL, Local Loopback Control
RS-232/V28
18
NC
Output
DTR, Data Terminal Ready
RS-232/V.28
20
H
Output
RL, Local Loopback Control
RS-232/V.28
21
NC
Output
RI, Ring Indicator
RS-232/V.28
22
NC
Input
AuxClk (+/A), DTE Clock Output
RS-422/V.11
24
24
Output

V.35 Cable
V.35 Cable (PN:2534GT)


RS­422/RS­449/RS­485/RS­530

The RS‐422 and RS‐485 standards describe differential electrical signals but not connector or pin assignments. The RS‐530 and RS‐449 standards define specific connectors and pin assignments using differential signals. The differential signals on the card meet both RS‐422 and RS‐485 electrical specifications.


RS‐530 uses differential signals on a DB‐25 connector. The adapter DB‐25 connector follows this standard when the port jumpers are installed for RS‐422/485. Use any straight through 25 conductor DB‐25M to DB‐25F cable (such as MicroGate Part # CMF000) to connect the adapter to RS‐530 communications equipment.


RS‐449 uses differential signals on a DB‐37 connector. To use this standard install the RS‐422/485 jumpers for the port and use the MicroGate RS‐449 cable (Part # 2537FM).


The maximum data rate supported by the adapter when using RS‐530 or RS‐449 is 10Mbps. Cable length and signal loading may reduce the maximum usable data rate from this value.


RS‐422/RS‐530/RS‐449 Male DTE
 
 
DB25M
DB37M
 
Signal Name
Electrical Description
RS-530
RS-449
Direction
 
 
Pin #
Pin #
 
Earth/Shield Ground
-
1
1
-
TxD (+/A), Transmit Data
RS-422/V.11
2
4
Output
RxD (+/A), Receive Data
RS-422/V.11
3
6
Input
RTS (+/A), Request To Send
RS-232/V28
4
7
Output
CTS, Clear To Send
RS-232/V28
5
9
Input
DSR, Data Set Ready
RS-232/V28
6
11
Input
Signal Ground
-
7
19
-
DCD, Data Carrier Detect
RS-232/V28
8
13
Input
RxC (-/B), Receive Clock
RS-422/V.11
9
26
Input
DCD (-/B), Data Carrier Detect
RS-422/V.11
10
31
Input
AuxClk (-/B), DTE Clock Output
RS-422/V.11
11
35
Output
TxC (-/B) Transmit Clock
RS-422/V.11
12
23
Input
CTS (-/B), Clear To Send
RS-422/V.11
13
27
Input
TxD (-/B), Transmit Data
RS-422/V.11
14
22
Output
TxC (+/A), Transmit Clock
RS-422/V.11
15
5
Input
RxD (-/B), Receive Data
RS-422/V.11
16
24
Input
RxC (+/A), Receive Clock
RS-422/V.11
17
8
Input
LL, Local Loopback Control
RS-232/V.28
18
10
Output
RTS, (-/B), Request To Send
RS-422/V.11
19
25
Output
DTR (+/A), Data Terminal Ready
RS-422/V.11
20
12
Output
RL, Remote Loopback Control
RS-232/V.28
21
14
Output
DSR (-/B), Data Set Ready
RS-422/V.11
22
29
Input
DTR (-/B), Data Terminal Ready
RS-232/V.28
23
30
Output
AuxClk (+/A), DTE Clock Output
RS-422/V.11
24
17
Output

RS-530 Cable
RS-530 Cable (PN:CMF000)

RS-449 Cable
RS-449 Cable (PN:2537FM)


X.21

X.21 is an interface standard using differential signals on a DB‐15 connector. To use this standard, install the RS‐422/485 jumpers on a port and use the MicroGate X.21 cable (Part # 2515FM).


The X.21 signal names are different than those used by the adapter and other interface standards. The mapping of the X.21 signals to the adapter signals are shown in the table below.


The maximum data rate supported by the adapter when using X.21 is 10Mbps. Cable length and signal loading may reduce the maximum usable data rate from this value.


X.21 Male DTE
Signal Name
Electrical Description
DB25 Pin #
  DB15 Pin#
Direction
Earth/Shield Ground
-
1
1
-
T+, Transmit Data
RS-422/V.11
2
2
Output
R+, Receive Data
RS-422/V.11
3
4
Input
I+, Indicator (DSR/DCD)
RS-422/V.11
6,8
5
Input
Signal Ground
-
7
8
-
S-, Clock Input (TxC, RxC)
RS-422/V.11
9,12
13
Input
I-, Indicator (DSR/DCD)
RS-422/V.11
10,22
12
Input
X-, Clock Output (AuxClk)
RS-422/V.11
11
14
Output
T-, Transmit Data
RS-422/V.11
14
9
Output
S+, Clock Input (TxC, RxC)
RS-422/V.11
15,17
6
Input
R-, Receive Data
RS-422/V.11
16
11
Input
C+, Control (DTR)
RS-422/V.11
20
3
Output
C-, Control (DTR)
RS-422/V.11
23
10
Output
X+, Clock Output (AuxClk)
RS-x21/V.11
24
7
Output

X.21 Cable
X.21 Cable (PN:2515FM)