I am running an application with a USP-104-B10 + UAG-XK125 + UIA-0402N_0 + UIS-WCB2_1 + UID-W1616R_2. The system has been running fine for a while, then stopped working without an obvious reason.
After power up, all the I/O modules start a normal boot (status LED: GREEN slow blink). Then operate for a split second, followed by a reboot (status LED: GREEN fast blink) of all modules. This continues in an endless cycle until after about 30-60 seconds the status LED's show a RED slow blink and the I/O's remain off. After each reboot the I/O are working for a split second. A while later the HMI reports "CPU Error Detected / Communication with the CPU cannot be established" followed by CPU in Stop Mode.
Seller advised to exchange the CPU but because I took the time to investigate and found the problem in the UIS-WCB2.
Disconnection of the 24V supply to the UIS-WCB2 module solves the problem!! However when I disconnect, the status LED of that module remains RED. The moment I reconnect the supply, the system goes back into the rebooting sequence.
I have checked the power supply to the UIS-WCB2. The 0V/24V power supply is shared with the supply of the HMI panel following the installation manual. Grounding is connected to all modules and all I/O's, including the power supply, are isolated from the rest of the installation.
The UIS-WCB2 digital outputs (O2 up to O9) in source configuration are connected to relays and the high speed input is connected to a rotational encoder.
So in short I tried the following:
Disconnect all I/O's, connect 24 V to pin +V: Problem starts instantly
Connect all I/O's, disconnect 24V to pin +V: All I/O'S work!!! Status LED remains RED!!!
I would appreciate some advice.
What could be causing this?
Can I continue to operate the system without further damage (UIS-WCB2 outputs are now powered by the CPU)?
Is it firmware related? Currently running version 1.22.9
Do I need to replace the UIS-WCB2? It has been in operation for a few hours only but surpassed its warentee period while in storage.