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Magnum PXR accessories
MAGNUM PXR PRODUCT GUIDE
PA013006EN September 2022 www.eaton.com
4
Communication accessories
Modbus_RTU communications
The Modbus RTU port is integrated for certain trip unit
styles. This provides communication from the trip unit to
a field Modbus network using the RS485 physical layer.
When powered, the trip unit will be able to communicate
via the secondary terminals labeled MBA, MBB, and MBG
as a responding (server) device. Recommended Modbus
cable is twisted pair having an aluminum/mylar foil shield
with drain wire.
The trip unit can support a maximum of 122 registers (244
data bytes) in a single Modbus transaction. The trip unit
responds to function codes 02, 03, 04, 06, 08, and 16.
Table 19. Trip Unit Registers
Register number
Definition
Data range
404000
Baud rate
00 = 9600 bits/s
01 = 19200 bits/s (factory default)
02 = 38400 bits/s
03 = 57600 bits/s
404002
Parity
00 = None
01 = Odd
02 = Even
404003
Stop bit
00 = 1 bit
01 = 2 bits
CAM - Communications adapter modules
All styles of the Magnum PXR trip unit support
Communication Adapter Modules (CAMs). These modules
provide communication to either Modbus RTU or Profibus
field networks.
Table 20. CAM Modules
Network
Module
Instruction leaflet
Ethernet (Modbus_TCP)
PXR-ECAM-MTCP
IL0131132EN
Profibus DP
PXR-PCAM
IL120009EN
These modules are remotely mounted on a DIN rail and
field-wired into the trip unit using the circuit breaker’s
secondary terminal block. The field bus is then wired to
a connection on the CAM module. See Terminal Block
Section for secondary wiring terminals.
Figure 72. PXR-ECAM module
