Re-Creating the IO Table in CX-Progammer
Written by Gareth Lyons
Updated at May 27th, 2024
Scenario
The PLC IO table may need to be re-created for CX-ONE PLC's to accommodate the following situations:
- Replacing / Adding new IO Cards on existing installations
- To confirm IO addressing, if unable to transfer from PLC or is not backed up in project.
- To clear a particular defined IO Table Error on the PLC / specific card on the rack.
Info
It is assumed the user has basic knowledge of CX-Programmer and has performed necessary backups of the system
Please refer to these Precautions and Terms and Conditions which relate to the information provided before proceeding
Warning
Pay close attention, as not following this procedure correctly, you may initialize the CPU bus inadvertently, which can clear pre-defined settings in Special I/O cards. Make sure you create suitable backups for any system you work on.
If you replace IO card positioning on the rack and dependent on the cards being utilized, be aware to check the IO memory space they occupy as this may shift when re-creating the IO table, affecting variable symbols tied to physical IO in the PLC, dependent on the existing configuration. Adding new cards to end of the rack positions, this is not a concern.
Example: For multiples of the same units such as digital IO units, which have no unit number rotary dials. These follow the same address structure of consecutive addressing, which will affect the IO addressing as follows if the cards are swapped positions in the rack (when using the automatic addressing method):
From:
[0000] CJ1W-ID212 - Address of CIO 0.00-0.15
[0001] CJ1W-OD212 - Address of CIO 1.00-1.15
To:
[0000] CJ1W-OD212 - Address of CIO 0.00-0.15
[0001] CJ1W-ID212 - Address of CIO 1.00-1.15
For cards that have rotary dials for Unit Numbers, if not changing these existing numbers, these can be moved around the rack freely as they preallocate memory areas based on the Unit Number providing a defined offset.
Please read relevant documentation on IO cards for more information on addressing.
Solution
- Make sure PLC is in Program Mode. Select 'IO Table and Unit Setup':
- Highlight Rack where you want to recreate IO table. In this case select 'Main Rack'. Then select 'Options'->'Create':
- Create the IO Table. Select YES:
-
Decision TreeWhen asked to 'Initialise CPU Bus Settings':Delete
Warning
Do you want to factory default / initialise / clear all memory of the PLC rack and IO Cards (this will clear IO card settings)?
-
Yes
-
No
- Add Button
select Yes if you want to initialise and factory default the rack.This content will be shown (depending on) when button above is clickedSelect Yes if you want to initialise and factory default the rack.
Select NO to retain Special IO Cards memory
- Select Transfer, which will transfer IO table and all special IO unit parameters:
- IO table will be created on CPU and transferred from the PLC into CX-Programmer project:
