12 • High Pressure CO2 Controller Installation and Operation Manual
3
The MODBUS Network
Although the High Pressure CO2 controller can
operate as a stand-alone controller, it relies on an E2
unit for advanced features such as remote dial-in/dial-
out, logging, and alarm control. The High Pressure
CO2 controller uses an RS485 network connection to
communicate with E2 site controllers.
3.1. Wiring Types
Retail Solutions specs Belden #8761 shielded
twisted pair cables for use as MODBUS wiring (or
Belden #82761 and Belden #88761 for plenum
installations).
If the recommended cable is not available in your
area, be sure the wiring meets or exceeds the
following specs:
Shielded?
Yes
Conductor Type
Twisted Pair
Gauge
18 - 24 AWG
Capacitance between
signal wires
31 pF/ft or less
(9.45 m) or less
Capacitance between
signal and shield
59 pF/ft or less
(17.98 m) or less
Nominal Impedance
120
50
3.1.1. Daisy Chains
Connect the MODBUS network cable to the three-
terminal connector on the E2 COM port you wish to
assign as MODBUS. Reverse the polarity of +/- on
the RS485 cable between the E2 and the High Pres-
sure CO2 controller.
Summary of Contents for 818-9010
Page 1: ...026 1731 Rev 0 01 DEC 2014 High Pressure CO2 Controller Installation and Operation Manual ...
Page 2: ......
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Page 19: ...Figure 3 1 MODBUS Networking 13 ...
Page 45: ...Figure 10 29 Override Screen 39 ...
Page 49: ...Figure 12 2 High Pressure CO2 Device Wiring and Network Connection 43 ...