Watlow 12LS Controller - Manual (Page 30)

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3.5 COMPUTER SERIAL COMMUNICATIONS
The ANAFAZE 12LS offers two types of serial communications: RS- 232 and RS-485. The RS-232 is used primarily
for local communications of up to the recommended RS-232 distance of 50 feet. It can only be used with one
ANAFAZE 12LS. More than one unit requires RS-485
The RS-485 is a voltage balanced, 4-wire, long distance, multi- point transmission interface. Up to 32 addresses can be
set in the 12LS for one communication line.
Units must be ordered for the RS-485 communications, otherwise the factory standard of RS-232 will be supplied with
the ANAFAZE 12LS.
3.5.1 RS-232 CONNECTIONS
The optically-isolated RS-232 interface is connected using the Communications terminal block 1. See Table 3-3 for
connections.
|--------------------------------------------------------------|
¦ TABLE 3-3. RS-232 CONNECTIONS ¦
|--------------------------------------------------------------¦
¦ Computer Connector ¦ 12 LS ¦
|------------------------------¦ TB 1 Pin Nr. ¦
¦ DB 25 ¦ DB 9 ¦ ¦
|--------------¦---------------¦-------------------------------¦
¦ RX Pin 3 ¦ RX Pin 2 ¦ TX Pin 26 ¦
¦ TX Pin 2 ¦ TX Pin 3 ¦ RX Pin 25 ¦
¦ GND Pin 7 ¦ GND Pin 5 ¦ GND Pin 23 ¦
|--------------------------------------------------------------|
The computer pins are for the normal 25 pin RS-232 connector [DB25] and the normal 9 pin connector [DB9]. On
some computers transmit TX and receive RX may be reversed. Please check your computer manual for details.
3.5.2 OTHER RS-232 LINES
Some host computers or other RS-232 devices use additional communication lines that are not required by the 12LS.
These include:
RTS - Ready to Send DSR - Data Set Ready
CTS - Clear To Send DTR - Data Terminal Ready
If the host computer uses RTS and CTS or DSR and DTR, these lines should be connected together in pairs [or as
shown in the computer manual]. Normally this is done in the RS-232 connector hood at the host computer.
Alternately, the effect of these lines can be eliminated in software. The ANAFAZE 12LS is ready to receive data;
therefore these lines are not required.