Emerson Control Link, Инструкция по установке и эксплуатации

Страница: 21 / 42

Wiring Types Network Wiring and Configuration • 15
field. You will see one of the following messages:
• Online - The Control Link ACC is communicating
normally.
• Offline - The Control Link ACC is not
communicating, has not been commissioned, is not
functional, or is not powered up. Verify the Control
Link ACC is powered up, wired correctly, and has
the proper network address, baud rate, and parity
(see Section 11, Troubleshooting Control Link
ACCs and the ECT MODBUS Network ).
• Unknown - The Control Link ACC is not
communicating or has not been commissioned.
Verify the Control Link ACC is powered up, wired
correctly, and has the proper network address, baud
rate, and parity (see
Section 11, Troubleshooting
Control Link ACCs and the ECT MODBUS
Network ).
• No Port - No port is set up in the E2 Serial
Configuration Manager to be a MODBUS port.
Follow the instructions in Section 7.2.1., Setup
Network Ports on page 11).
• Wrong FW Rev - This message is likely caused by
the Control Link ACC having a firmware version
older than the minimum revision required by E2 for
communication. Replace the Control Link ACC
with a new controller that has the latest version of
firmware on it.
7.3. Wiring Types
Emerson specifies 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:
Figure 7-11 -
Network Summary Screen
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 be-
tween signal and
shield
59 pF/ft or less
(17.98 m) or less
Maximum Length 4000 ft/18 to 22 AWG
(1219.2 m)
2500 ft/24 AWG
(762 m)
Nominal

Impedance
120

50
