A-1
APPENDIX A. RS232 D-CONNECTOR PIN FUNCTIONS
Pin Number
Function
1
Protective ground, internally connected to pin 7
2
Tx
receive data line, from DTE
3
Rx
transmit data line, to DTE
4
RTS request to send, input from DTE
5
CTS clear to send, to DTE, normally held high by the MCR1
6*
DSR data set ready, to DTE, held high at +5 V
7
Signal ground
8*
DCD data carrier detect, to DTE, held high at +5 V
* directly connected to the internal 5V supply, do not short to ground.
1.
Unlike the CSM1/ SC532, only RTS is required for telecommunications mode; the DTR line is
not used.
2.
Only pins 2, 3, 4 and 7 need to be connected for use with the CSMCOM program. For
connection to a PC these pins should be connected to the equivalent function pins on the PC's
DTE interface.
