User guide

Watlow Series 97 Wiring ■ 3.11
NOTE:
Successful installation
requires five steps:
• Choose the controller’s
hardware configuration
and model number
(Appendix);
• Choose a sensor
(Chapters 3 and 6, and
Appendix);
• Install the controller
(Chapter 2);
• Wire the controller
(Chapter 3) and
• Configure the controller
(Chapters 4, 5 and 6).
NOTE:
The CMC converter
requires an external
power supply when used
with a laptop computer.
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WARNING:
To avoid damage to
property and equipment,
and/or injury of loss of
life, use National Electric
Code (NEC) standard
wiring practices to install
and operate the Series 97.
Failure to do so could
result in such damage,
and/or injury or death.
NOTE:
If the system does not
work properly, it may need
termination resistors at
each end of the network. A
typical installation would
require a 120-ohm resistor
across the transmit/receive
terminals (19 and 21) of
the last controller in the
network and the converter
box or serial card. Pull-up
and pull-down resistors
may be needed to main-
tain the correct voltage
during the idle state.
Figure 3.11a — EIA-232 to EIA-485 Conversion
B&B Converter (B&B Electronics Manufacturing Company, [phone]).
CMC Converter (CMC Connecticut Micro-Computer, Inc., 800-426-2872).
Figure 3.11b — Termination for EIA-232 to EIA-485 Converter
+5V
B
A
GND
T+/R+
T-/R-
Com
1KΩ
120Ω
1KΩ
Converter box
termination
with pull-up
and pull-down
resistors.
9VÎ (dc) (see note)
120VÅ (ac)
COM.
T-/R-
T+/R+
0219-0217-0000
7 ft. comms cable
EIA-232
ADA485L
EIA-485
A
B
A
B
G
9VÎ
G
DI/ODI/O
21
19
20
T-/R-
TD (A)
TD (B)
RD (A)
RD (B)
T+/R+
120V~(ac)
EIA-232 EIA-485
EIA-485
Power Supply
AD-1210
+
–
GND
GND
COM.
19
20
21
485OIC
+12VÎ(dc)
+12VÎ(dc)
(232 power)