Watlow CLS200 - Manual (Page 63)

CLS200 Series User’s Guide Chapter 2: Installation
Doc.# 0600-3050-2000 Watlow Anafaze 47
EIA/TIA-485 Interface
To communicate with more than one CLS200 series con-
troller on a controller network, or to use communication ca-
ble lengths greater than 50 feet (15.2 m) from PC to
controller, you must use EIA/TIA-485 communications.
When using EIA/TIA-485 communications, you must at-
tach an optically isolated EIA/TIA-232 to EIA/TIA-485 con-
verter to the computer.
Figure 2.32 and Figure 2.33 show the recommended system
wiring. To avoid ground loops, use an optically isolated
EIA/TIA-232 to EIA/TIA-485 converter between the com-
puter and the EIA/TIA-485 network.
Figure 2.32 EIA/TIA-485 Wiring
Cable Recommendations
Watlow Anafaze recommends Belden 9843 cable or its
equivalent. This cable includes three 24 AWG (0.2 mm 2 )
shielded, twisted pairs. It should carry signals of up to
19.2k baud with no more than acceptable losses for up to
4,000 feet (1,220 m).
EIA/TIA-485 Network Connections
Walow Anafaze recommends that you use a single daisy
chain configuration rather than spurs. Run a twisted-pair
cable from the host or the converter to the first CLS200,
and from that point run a second cable to the next CLS200,
and so on. (See Figure 2.33.)
If necessary for servicing, instead of connecting each con-
troller directly into the next, install a terminal strip or con-
nector as close as possible to each CLS200, run a
communications cable from one terminal strip to the next
and connect the controllers to the bus with short lengths of
cable.
EIA/TIA-485 Converter
TXA/TDA/TX-
TXB/TDB/TX+
RXA/RDA/RX-
RXB/RDB/RX+
RXA 25
RXB 23
TXA 26
TXB 24
RXA 25
RXB 23
TXA 26
TXB 24
Do not
A
B A
B
connect
shield to
CLS200
First CLS200 Last CLS200
JU1 JU1
Personal Computer