Hardware reference guide

Modbus Plus NOMs
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The NOM hardware defaults to bridge mode when the front panel switch is set to
RTU or ASCII mode. When networking controllers, a panel device connected to the
NOM Modbus port can communicate with the controller to which it is conected, as
well as log into any nodes on the Modbus Plus network.
Setting the slide switch to the top position assigns ASCII functionality to the port. The
following comm parameters are set and cannot be changed.
Setting the slide switch to the middle position assigns remote terminal unit (RTU)
functionality to the port; the following comm parameters are set and cannot be
changed.
Setting the slide switch to the bottom position gives you the ability to assign comm
parameters to the port in software; the following parameters are valid.
ASCII Comm Port Parameters
Baud 2,400
Parity Even
Data Bits 7
Stop Bits 1
Device Address Rear panel rotary
switch setting
RTU Comm Port Parameters
Baud 9,600
Parity Even
Data Bits 8
Stop Bits 1
Device Address Rear panel rotary
switch setting
Valid Comm Port Parameters
Baud 19,200 1,200
9,600 600
7,200 300
4,800 150
3,600 134.5
2,400 110
2,000 75
1,800 50
Data Bits 7 / 8