User manual
PAGE 28 30 JUN 2000 MAN0051-01
APPENDIX A
A.2 PLC Serial Port (COM2)
The Series 90-30 PLC serial port is compatible with RS-422. An RS-232 to RS-422 converter is required
to interface to systems that provide RS-232 compatible interfaces. This part is available from Horner
APG (Part #HE693SNP232A). The Series 90-30 PLC, RS-422 serial port provides the physical
connection for SNP communication. This port is a 15-pin D-type female connector located on the Series
90-30 PLC Power Supply. Figure A.2 shows the serial port orientation and connector layout for the
Series 90-30 PLC types. Table A.2 shows the pin numbering and signal assignment applicable to the
PLC.
Table A.2 – COM2 Pinout
Pin Number Signal Name I/O Description
1 Shield
2 N.C. No Connection
3 N.C. No Connection
4 N.C. No Connection
5 +5V * Output +5V Power for HHP and RS-232/485 Converter
6 -RTS Output Request To Send
7 GND Ground
8 CTS Input Clear To Send
9 RT * Terminating Resistor for RXD **
10 -RXD Input Receive Data
11 RXD Input Receive Data
12 -TXD Output Send Data
13 TXD Output Send Data
14 RTS Output Request To Send
15 -CTS Input Clear To Send
* Signals available at the Connector (RS-422) on the Series 90-30 PLC but not included in the RS-422
specification.
** Termination resistance for the Receive Data (RXD) signal needs to be connected only on units at the
end of the lines. This is accomplished by connecting a jumper between pins 9 and 10 inside the 15-pin
D-shell.
Figure A.2 – Series 90 PLC, RS-422 Serial Port Connector Configuration (COM2).