Hello, I am in need of setting up a message instruction to transmit data between two SLC-505 PLCs. I am experiencing difficulties in transferring the data successfully. I have provided pictures illustrating the configuration and setup for reference. I have set a timer.dn bit to initiate the message instruction, but I am not observing the .en bit turning true. The data being transferred is a pressure value in floating point format, which I have converted to an integer before transmission. Despite no apparent errors, the .en bit never activates. Is there a way to utilize the .ER bit to identify errors in the MSG instruction? I would appreciate it if you could review the screenshots and point out any errors on my part. Thank you for your assistance.
If you are experiencing a full queue space with message buffers, take a look at the number of MSG instructions you have. Consider staggering them to optimize performance.
Thank you for providing assistance. I have only programmed one message instruction on this programmable logic controller (PLC).
Ones_Zeros expressed gratitude for the assistance with a PLC issue involving a single message instruction. Do you have additional PLCs, HMIs, or programmers linked to this PLC? Furthermore, what is the reasoning behind selecting "YES" for multihop in SLC to SLC communications? Your insight is appreciated.
I made a mistake with the multihop feature thinking it was necessary. Can I remove it? I need to confirm that no other PLCs are sending data to the PLC I am trying to read from using the message instruction.
I have noticed that another programmable logic controller (plc) is transmitting data to the plc I am currently retrieving information from, causing a buffer error. They seem to be out of sync. How can I resolve this buffer error issue? Your assistance is greatly appreciated.
Hi there! From what I've noted so far in your configuration, you are appropriately initiating the MSG instruction with a Timer.dn bit. However, if you're not seeing the .EN bit turning true, some glitch might be occurring. An .ER bit can surely help indicate errors, just append .ER to your MSG instruction; for instance, YourMessageInstruction.ER. However, from my understanding, you're transmitting an integer; make sure the destination PLC can process this correctly. Furthermore, double-check your MSG instruction setup; the source and destination elements must be correctly referenced. Lastly, ensure your communication setup is running properly - it could be a network issue as well. I hope you find this advice helpful and please keep us updated on your progress!
Sure, I'd be glad to assist! Looking at the SLC-505's messaging capabilities, it seems like you have the basis covered with your timer and conversion. Regarding your .en bit issue, double-check that you're addressing it correctly; it should naturally turn true when your timer.dn bit is addressed properly. To use the .ER bit effectively, you have to check it immediately following the .EN bit becoming false. If there’s a non-zero value, then some error has occurred. Also, I would suggest checking your connection path in your message instruction. More often than not, communication paths can contribute to such errors. Can you also verify if you're seeing any .DN bit activity? This can give a more detailed picture.
From your description, it appears you've done a solid job with your data setup and conversion. The activation of the .EN bit can sometimes be dependent on microsecond-level timing nuances, so it's important not to overlook that aspect. As for using the .ER bit, yes, it can be a very useful tool for troubleshooting MSG instructions as this bit will turn true if there's an error in the reading or data transmission. Try checking the status bit S:6/8 (Comm Error Bit) and the error code S:6/1 (Comm Error Code) to diagnose the underlying issue. Remember that the .EN bit will only go true at the start of the transmission, it won't necessarily hold true. So, analyzing your program for these bits might reveal some insightful information. Lastly, please double-check if you're pointing your message instruction towards the correct tags and the timer setting is optimal. Looking forward to your updates.
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Answer: Answer: To troubleshoot data transmission issues, ensure that the message instruction setup is correct, check for errors in the configuration, validate data conversion processes, and monitor relevant status bits like .en and .ER.
Answer: Answer: The .en bit may not activate due to configuration errors, improper data conversion, or other setup issues. Review your configuration, data format conversions, and message instruction settings to identify the root cause.
Answer: Answer: Yes, the .ER bit in the message instruction can help identify errors. Monitor this bit to troubleshoot issues related to data transmission between the SLC-505 PLCs.
Answer: Answer: To transmit floating-point data successfully, ensure proper data conversion to integer format before transmission, validate message instruction setup, and monitor status bits like .en and .ER for error identification.
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