SIGMA MRX Series User Manual
Page 19
APPENDIX A – SCI PROTOCOL AND INTERFACE
A9
9 PIN 'D' RS-232 PIN ASSIGNMENT
PIN
#
FUNCTION
∗
DIRECTION
1
N/C
----
2
RECEIVE DATA
INPUT to SCI-MRX
3
TRANSMIT DATA
OUTPUT from SCI-MRX
4
DATA TERMINAL READY OUTPUT from SCI-MRX
5
SIGNAL
GROUND
N/A
6
DATA SET READY
INPUT to SCI-MRX
7
READY TO SEND
OUTPUT from SCI-MRX
8
CLEAR TO SEND
INPUT to SCI-MRX
9
N/C
----
The Pin assignments noted are per the RS-232 standard. Although the standard defines the
use of twenty five (25) Pins, only nine (9) are required for PC serial communications. Of those nine
pins, only seven are required for communication to the SCI when handshaking is required. If
handshaking is not required only three pins will be active. There is no need to jumper the
handshaking pins when unused. Consult the control device manufacturer’s data sheet to determine
proper wiring.
PIN OUT
SCI-MRX Serial Port
5 1
9
2
3
4
8 7 6