COM1
C–5
COM1
The null-modem COM1 cable—shipped with each
MCS—directly connects the MCS to an MCS workstation.
The cable provides
❐
A 9-pin D-shell male that connects to the MCS COM1
port
❐
A 25-pin D-shell female that connects to an MCS
workstation
Note
Do not use the COM1 cable in the opposite
direction—use adapters to make the connection.
When building your own COM1 cable, use no more than
50 feet (15.2 meters) of Belden 9612/9613 computer cable,
or equivalent.
Table C–2 lists the pin assignments for the MCS COM1
port and a 25-pin connector on the MCS workstation.
Table C–2. COM1 Port Pin Assignments
9-Pin Function
Description
25-Pin
Function
Description
2
RxD
Receive data
→
2
TxD
Transmit data
3
TxD
Transmit data
→
3
RxD
Receive data
4
DTR
Data terminal ready
→
6
DSR
Data set ready
8
DCD
Data carrier detect
5
SG
Signal ground
→
7
SG
Signal ground
6
DSR
Data set ready
→
20
DTR
Data terminal ready
1
DCD
Data carrier detect
7
RTS
Request to send
→
5
CTS
Clear to send
8
CTS
Clear to send
→
4
RTS
Request to send