Emerson 026-1726, Installation And Operation Manual, Page: 19 / 32

RS-485 Communications Network Setup and Commissioning • 13
not being used.
8. Repeat
Steps 5
and
6
until each Energy Meter de-
vice has been commissioned.
9. When finished, press  to return to the Network
Setup menu, then press

-
Network Summary
(
Figure 6-4
). Locate the Energy Meters you set up,
and look at each device’s status in the
Status
field.
You will see one of the following messages:
•
Online
- The Energy Meter is communicating nor-
mally.
•
Offline
- The Energy Meter is not communicating,
has not been commissioned, is not functional, or is
not powered up. Verify the Energy Meter is powered
up, wired correctly, and has the proper network ad-
dress, baud rate, and parity.
•
Unknown
- The Energy Meter is not communicating
or has not been commissioned. Verify the Energy
Meter is powered up, wired correctly, and has the
proper network address, baud rate, and parity.
•
No Port
- No port is set up in the E2 Serial Config-
uration Manager to be a MODBUS port.
•
Wrong FW Rev
- This message is likely caused by
the Energy Meter having a firmware version older
than the minimum revision required by E2 for com-
munication. Replace the Energy Meter with a new
controller that has the latest version of firmware.
6.3. RS-485 Communications
6.3.1. Daisy-chaining Devices to the Ener-
gy Meter
The RS-485 slave port allows the Energy Meter to
be connected in a daisy chain with up to 63 two-wire
devices. In this manual, communications link refers to
a chain of devices that are connected by a communi-
cations cable.
NOTES:
• The Energy Meter polarity markings are the inverse
of E2; connect the Energy Meter +Data wire to the
E2 RS485 - terminal and connect the Energy Meter
-Data wire to the E2 RS485 + terminal. The shield
cable should be connected to the right most terminal.
• The terminal’s voltage and current ratings are com-
pliant with the requirements of the EIA RS-485
communications standard.
• The RS-485 transceivers are ¼ unit load or less.
• RS-485+ has a 47 kOhm pull up to +5V, and RS-
485- has a 47 kOhm pull down to Shield (RS-485
Figure 6-6 -
List of MODBUS Devices
Figure 6-7 -
Network Summary Screen
Figure 6-8 - Energy Meter Daisy Chain
E2
MODBUS
device
#1 #3
REVERSE POLARITY
Energy Meter +Data to the E2 RS485 -
Energy Meter -Data to the E2 RS485 +
MODBUS
device
MODBUS
device