Hardware reference guide

CPU Modules
186
35013379 11/2011
NOTE: Information in the Code column is visible only with the Flash download utility.
Front Panel Slide Switch
The slide switch, located on the front of the CPU, is used to select the comm
parameter settings for the Modbus (RS232) ports. Three options are available.
1. Setting the switch to the top position assigns ASCII functionality to the port.
2. Setting the switch to the middle position assigns remote terminal unit (RTU)
functionality to the port.
3. Setting the switch to the bottom position lets you assign comm parameters to the
port in software.
Slide switch::
NOTE: The CPU 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 CPU Modbus port can communicate with the controller to which it is
connected, as well as log into any nodes on the Modbus Plus network.
The following table shows the ASCII comm port parameters.
7 300 EXEC not loaded
301 EXEC Checksum
8 8001 Kernal prom checksum error
8002 flash prog / erase error
8003 unexpected executive return
LED Error Codes
Number of Blinks Code Error
ASCII Comm Port Parameters
Baud 2,400
Parity Even
Data Bits 7
Stop Bits 1
Device Address Rear panel rotary switch setting