Communication failure of the operation panel for the UOP reforming CRCS system (APACS)
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Some time ago, the communication with the operation panels on the CRCS cabinets in our company’s reforming units was lost; however, the PLCs were still able to function normally. UOP engineers were called in twice, but they were unable to resolve the issue. They said that the APACS system currently in use is too old, and no one at UOP knows how to work with it, so they can’t fix it. Now we have to rely on the DCS for operations, but we can’t view or modify certain parameters. I would like to ask the experts if you have encountered similar problems and how to deal with them
This problem is indeed quite tricky. The communication issues with the APACS system that you’re facing are actually something that many older factories have encountered as well. UOP says no one understands this old system, and that’s true—these DCS systems from the 1990s are no longer in production, and even the original manufacturers’ engineers are not familiar with them. I suggest trying these approaches: 1. Don’t rush to fix the hardware; first check the communication cables and connectors. The physical connections are the most common source of problems in old systems; sometimes it’s due to oxidation at the connectors or loose network cables. 2. If the wiring is fine, you can try restarting the APACS operation station and controller. Old systems are prone to software errors after running for a long time; restarting them might resolve the issue. 3. Contact some professional third-party repair companies – there are experienced technicians who specialize in fixing such old systems, and they are even more reliable than the original manufacturer. Our factory has already sought such teams in the past. 4. In the long run, it is indeed necessary to consider a system upgrade. It’s becoming increasingly difficult to find spare parts for the old system; even if it’s fixed this time, other problems might arise next time. For now, it’s okay to use DCS as a temporary solution, but as you said, the inability to view certain parameters does affect operations. If time is of the essence, the key parameters can first be connected to the DCS for temporary display; it’s a bit troublesome, but it can help in an emergency. I really relate to what you’re going through; we faced a similar problem with our equipment the year before last, and it was only after consulting an experienced expert that we were able to resolve it. I can recommend contact details if needed. .
Our installation has encountered similar issues as well; we found an engineer who used to work at UOP and got the problem resolved by getting in touch with him through his business card
Thank you for the suggestion. We have roughly checked the hardware and communication lines, and they seem to be in good condition; however, we don’t dare make any changes as the main device is still under production. The company has been performing poorly over the past two years, so upgrading and renovation will likely have to wait for a few more years. Try to find an expert to come on site and take a look first
Thank you for providing the contact information; we’ll give it a try by getting in touch first.
This post was last edited by Haishen Qiuwang on 2026-1-3 at 20:38. We got in touch with Engineer Zhang and found that there had been previous communications via ACCS as well; we didn’t expect that he is also involved with CRCS. He came to the site twice and finally resolved the issue; it has been working properly for about a month now. The communication problems were likely due to issues with OPC and the hardware. Thank you very much for the information you provided. :handshake