Measurement Computing Serial488/4 - Manual (Page 31)

Section 2 Getting Started
2.19
Table 2-2. RS-232 Serial Port Pin Connections
Pin Description Input/Output
1 No connection
2 Receive data (RxD-) Input
3 Transmit data (TxD-) Output
4 No connection
5 Ground
6 No connection
7 Request to send (RTS+) Output
or 16 x baud clock Output
8 Clear to send (CTS+) Input
or 16 x baud clock Input
9 No connection
Table 2-3. RS-422 Serial Port Pin Connections
Pin Description Input/Output
1 Ground
2 Clear to send positive (CTS +) Input
or 16 x baud clock Input
3 Clear to send negative (CTS -) Input
or 16 x baud clock Input
4 Transmit data positive (TxD +) Output
5 Transmit data negative (TxD -) Output
6 Request to send positive (RTS +) Output
or 16 x baud clock Output
7 Request to send negative (RTS -) Output
or 16 x baud clock Output
8 Receive data positive (RxD +) Input
9 Receive data negative (RxD -) Input