Hello everyone! I'm currently working on a historian project where I am documenting six key events within my PLC (Programmable Logic Controller) logic. I've kept the tag names quite basic, such as Alarm01 and Alarm02. While creating detailed descriptions for each alarm or event associated with these tags is an option, I think it would be amazing to implement a method that allows me to input a specific description in real-time while online. Does anyone have any strategies or techniques for achieving this? I haven’t researched it thoroughly yet, but I’d love to save some time and hear any ideas or suggestions you might have. Thank you for your insights!
I attempted to implement dynamic alarm messages using FTAE (Field-Tested Alarm Engine) and was not entirely pleased with the results. One major limitation is that the messages themselves are not accessible for program manipulation. My initial thought was to incorporate embedded tags within the messages; however, this approach also fell short of expectations. For instance, if you include an ADD instruction at the start of each rung in your alarm routine, which resets to zero during every scan, the value generated becomes ineffective in FTAE messages. This is due to the definable yet unpredictable delay that occurs between executing an FTAE instruction and the actual message construction, which ultimately leads to misleading outputs. On the other hand, when it comes to custom alarm configurations, it's entirely feasible to create dynamic messages that can even be updated through an HMI (Human-Machine Interface). Typically, the most effective strategy involves utilizing arrays for the alarm conditions, a corresponding array for the alarm latches, and another for the alarm messages. This setup allows for indexed addressing to keep everything organized. The simplest implementation would consist of two Boolean arrays for alarm conditions and latches, along with an array of strings for the messages. For more complex scenarios, you might opt for arrays of DINTs (Double Integers) to simplify the process of checking for active alarms or introduce additional Boolean arrays to manage individual alarm resets while displaying their Unacknowledged or Acknowledged status. This approach not only enhances the dynamic nature of alarm messaging systems but also improves usability and integration with modern HMI technologies.
Caution is advised for those who lack experience. As noted by a user, the actual messages are not readily accessible for program manipulation. However, one potential (though not recommended) approach could involve creating User-Defined Types (UDTs) that mimic the structure of ALMD and ALMA tags. You could then copy the ALMD into the UDT, modify the string (as the UDT would be available to the PLC), and subsequently copy it back. While achieving the correct byte sequence in the proper order can be challenging, it is certainly feasible.
Aardwizz suggested an interesting theoretical approach (though I don't necessarily endorse it) involving the creation of User Defined Types (UDTs) that mimic the data structure of ALMD and ALMA tags. This would involve copying the ALMD into the UDT, modifying the string—since it would be accessible from the PLC—and then transferring it back. However, accurately managing the byte arrangement can be quite challenging. In my opinion, a more straightforward solution would be to develop your own version or utilize a SCADA system, such as Ignition, which excels at handling alarms directly from the Human-Machine Interface (HMI).
✅ Work Order Management
✅ Asset Tracking
✅ Preventive Maintenance
✅ Inspection Report
We have received your information. We will share Schedule Demo details on your Mail Id.
Join hundreds of satisfied customers who have transformed their maintenance processes.
Sign up today and start optimizing your workflow.