Watlow CAS200 - Manual (Page 40)

Chapter 2: Installation CAS200 User’s Guide
28 Watlow Anafaze
Figure 2.15 Recommended System
Connections
Signal Common
For usual installations, do not connect the dc commons of
the scanners together or to the converter or host device.
Use an optically isolating 232-to-485 converter to prevent
problems with sensor readings.
Termination
For EIA/TIA-485 signals to be transmitted properly, each
pair must be properly terminated. The value of the
termination resistor should be equal to the impedance of
the communications cable used. Values are typically 150 to
200
Ω.
The receive lines at the converter or host device should be
terminated in the converter, the connector to the host
device or the device itself. Typically the converter
documentation provides instructions for termination.
Use a terminating resistor on the receive lines on the last
scanner on the 485 line. Set jumper JU1 in position B to
connect a 200
Ω resistor across the receive lines. See
Changing Communications on page 81.
WATLOW ANAFAZE CLS200 WATLOW ANAFAZE CLS200 LO OP LOOP PR OC ES S PROCESS UN IT S UN ITS
AL AR M ALARM SE TP OI NT SETPOINT ST AT US STA TUS OU T% OUT%
M AN AU TO MAN
AU TO C HN G SP CHN G SP
A LA RM A CK ALARM
A CK
R AM P S OA K RAMP
SO AK
YE S YE S N O NO BA CK BACK EN TER ENTER WATLOW ANAFAZE CLS200 WATLOW ANAFAZE CLS200 LO OP LOOP PR OC ES S PRO CESS UN IT S UN ITS
AL AR M ALARM SE TP OI NT SETPO INT ST AT US ST ATUS OU T% OUT%
M AN AU TO MAN
AUT O C HN G SP CHNG
SP
A LA RM A CK ALARM
ACK
R AM P S OA K RAMP
SOAK
YE S YES N O NO BA CK BACK EN TER ENTER WATLOW ANAFAZE CLS200 WATLOW ANAFAZE CLS200 LO OP LOOP PR OC ES S PROCE SS UN IT S UN ITS
AL AR M ALA RM SE TP OIN T SETPOIN T ST AT US STAT US OU T% OU T%
M AN AU TO MAN
AUT O C HN G SP CHNG
S P
A LA RM A CK A LARM ACK
R AM P S OA K RAMP
SOAK
YE S YE S N O NO BA CK BACK EN TER ENTER
Serial Port
232 Communications 485 Communications
Shielded Twisted Pair Cable Optically
Isolating
232-to-485
First CAS200 Second CAS200 Last CAS200
Converter