Goals and Symptoms

This resolution illustrates the steps necessary to change the Modbus Plus address on a High End Unity Quantum controller.

Causes and Fixes

The LCD screen on the front of the 140CPU6X1X0 controller will display the state of the controller as either "No Conf" for no configuration, "Stop" for configured but not running, and "Run" for configured and running.
This screen will also show the Modbus Plus status: MB+ when it is connected to a Modbus Plus network and can see the token being passed. It displays lower case mb+ when it is either disconnected from the network, or cannot see the token.
Changing the Modbus Plus address requires the following steps:
1. Press the button on the keypad twice and the display will show "Quantum Communications.
2. Press the button on the keypad once and the display will show "Communications TCP/IP Ethernet"
3. Press the button on the keypadonce and the display will show "Communications Modbus Plus"
4. Press the button on the keypad once to access the current Modbus Plus Address. Example "MB+ Address: 01"
5. Press the button to modify the Modbus Plus address. Use the button to toggle between the ones and tens digit of the address, and
use the button to change the value of the digit selected.
6. Choose a valid Modbus Plus Address from 1-64 that is not currently used on the Modbus Plus network then press on the keypad to save the chosen address.
7. Press the button three times to return to the initial screen.
NOTE: if there is a "DUP" indication on the display, you have chosen an address that is already in use.