Hardware reference guide
Network Configurations
52
35013379 02 October 2007
Modbus 
Plus 
Services
MSTR read/write register messagin
-Y-Y-Y
MSTR read/write Global Data 
messaging
-Y-Y-Y
MSTR get/clear local/remote statistics - Y - Y - Y
Config Extension Global Data Support - Y - Y - N
Config Extension Peer Cop Support - Y - Y - N
Distributed I/O Support - Y - Y - N
CPU Programming - - -
Executive Firmware Loading Support - Y - N - N
Type Service Description Native CPU Ports NOM 1-2 Ports NOM 3-6 Ports
Modbus Modbus 
Plus
Modbus Modbus 
Plus
Modbus Modbu
s Plus
g
6
Y
4
Y
4
Y
4
Note:  
1. Only supported on the 140CPU42402, 140CPU42412(A) and 
140CPU53414(A)/(B) Quantum Controllers.
2. The native CPU Modbus port can be disabled from bridge mode operation with 
the native Modbus Plus Port.
3. Modbus ports on NOMs are always in bridge mode with their associated 
Modbus Plus port.
4. Only one programmer connection can be logged in at a time to any CPU, and 
only one program monitor can be attached at a time to any CPU.
5. Modbus port parameters on NOMs 3-6 are defined by Modbus Port 3 in Concept 
and Modsoft when the comm parameter selector switch is in mem.
6. Up to 4 MSTR read/write register instructions can be serviced per CPU scan per 
Modbus Plus port.
This document provided by Barr-Thorp Electric Co., Inc. 800-473-9123 www.barr-thorp.com










