AB Micro820 to PVC400 Via Ethernet

I'm currently having some trouble in allowing the PVC400 component to communicate with the micro820 PLC. I am trying to alter the digital inputs of the plc with pushbuttons that are represented on the PVC400 however when any of the buttons are pressed the error "10:Write Error for Alias XXX, Controller PLC-1, Address is _IO_EM_DI_00, Communication Flag is 0" is shown. I have the PLC set up as slave however this seems to have made no difference. Is it possible to alter digital inputs using the AB PVC400? I am currently using CCW to program this set up.

You would generally NOT be able to influence inputs by means of the HMI nor the PLC program.

I thought that may be the case. I know that you can 'force' the state of any of the digital inputs into the PLC when it is in debug mode within CCW and was curious to find out if these inputs could be altered via an HMI. Thanks for your help.

The inputs are sampled by the PLC and likely placed in the input image table. If you could affect them via the HMI, at what point would the HMI relinquish control back to let the PLC use the actual inputs.

You can, obviously, have the HMI set a bit in the PLC that you can use in parallel with the real input to do something in your logic.

Gary_1991 said:

I'm currently having some trouble in allowing the PVC400 component to communicate with the micro820 PLC. I am trying to alter the digital inputs of the plc with pushbuttons that are represented on the PVC400 however when any of the buttons are pressed the error "10:Write Error for Alias XXX, Controller PLC-1, Address is _IO_EM_DI_00, Communication Flag is 0" is shown. I have the PLC set up as slave however this seems to have made no difference. Is it possible to alter digital inputs using the AB PVC400? I am currently using CCW to program this set up.

Click to expand...

To drive danatomega's point home...

Within CCW, in the Tag Editor for the PVc - when you create a new tag and open the "Address" ellipses, you are now looking at the "Variable Selector" window. Then you go to the "I/O - Micro820" tab, where you see the list of available I/O for the Micro820. This is where you selected the "_IO_EM_DI_00" digital input address for your PVc tag for your pushbutton. If you maximize that window, and look to the "Attribute" column, you will notice the digital and analog inputs are all "Read" only, and cannot be changed, whereas the digital and analog outputs are all "Read/Write". See attached...

The PVc can Read the Micro820's inputs, but not Write them.
The PVc can Read or Write the Micro820's outputs.

Generally, and as advised, your digital input will drive an internal tag or similar in the controller. You can parallel another direct contact off the input contact to drive the same tag from your PVc. Also, see attached...

Regards,
George

A little off topic, but I just installed CCW 7.0 and when I add a C400 to the project, it creates it as having firmware version 1.70. Our C400 came pre-loaded with 1.80 and when I try to download the HMI it fails (after successful connection).

I can't seem to find anywhere in CCW to change the firmware version, even when creating a new project and adding the C400 for the first time. On another computer CCW 7.0 always creates PVc projects as firmware 1.80. Anyone have any ideas?