Greetings, everyone! I am currently working on establishing Modbus communication between two Micro870 PLCs using RS485 and 2x2080-SERIALISOL plug-in modules. PLC1 has been configured as the master with a Baud Rate of 19200, No Parity, and set to a Modbus Role of Master, while PLC2 is configured as the Slave with a Baud Rate of 19200, No Parity, and Modbus Role of Slave with a Slave ID of 1. Despite these settings, I am encountering Error 130 during the message exchange on PLC1. I have consulted Rockwell Automation documentation, which suggests that Error 130 could indicate an issue with the Modbus address. However, after trying various address variations such as 4000, 40000, and 400001, I have not been able to resolve the error. Could anyone provide insights or suggestions on what may be causing this issue? Your input would be greatly appreciated.
This issue often arises when no configuration has been established in the Modbus Address Table. This can lead to communication errors and hinder the operation of the system. It is essential to properly configure the Modbus Address Table to ensure seamless data exchange between devices.
Indeed, you are right. I successfully set up the Modbus mapping, and the communication functioned flawlessly. Initially, I mistakenly assumed that the modbus mapping was only effective when utilizing the controller's serial port. However, I stand corrected. Much appreciation for the insight. Matter resolved. Cheers.
Hello, could you please share what you mapped? I am experiencing a similar issue and would greatly appreciate your help. Thank you.
Hello, shesame. Please ensure to check the Modbus Mapping in the Controller section of the CCW software. It is crucial to set up a proper Modbus mapping to ensure the correct functioning of your Modbus communication.
Hey there! I have worked with Micro870 PLCs using Modbus communication. Error 130 often indicates an address issue as you've mentioned. But apart from incorrect address entry, it can also arise due to addressing a non-existing area of the PLC. For instance, if you're trying to read a coil or register that doesn't exist or is out of range. Make sure you’ve selected the correct Modbus function code for what you're trying to achieve (perhaps function code 03 for reading holding registers?). Additionally, make sure you aren't simply converting the address - understanding how addresses map from the PLC to the Modbus protocol is crucial. For example: if '40001' is your PLC data address, this usually maps to Modbus register '0000'. Hope this can offer you a different perspective to approach the problem. Good luck!
Hi there! It indeed sounds like you've diligently followed the Rockwell Automation documentation, but the ongoing issue seems perplexing. Are you sure you've checked the PLC's communication cable properly? A malfunctioning or broken cable frequently results in a connection error like this. Even if it appears fine visually, a slight internal damage could cause communication glitches. Moreover, ensures to confirm that the Slave ID is correctly configured in both software and hardware. If everything else fails, try to loop back test each RS485 port to ensure PLC's serial port is in good working condition. Hope my suggestions help you troubleshoot effectively.
Hey there! I've also experienced the pesky Error 130 in Modbus communication. Have you looked into the time-out settings on your PLC1 master? Sometimes this error can occur if the response from the slave takes longer than the master's specified wait time. This could happen if there's a delay on the physical line or simply if the slave is busy. Another thing is ensuring that the Request Data Size is correctly set to match the number of registers on the Slave you want to read. Hope this helps. Let us know how it goes!
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Answer: - Error 130 during Modbus communication on the Micro870 PLCs could indicate an issue with the Modbus address settings.
Answer: - PLC1 should be configured as the Master with specific settings, while PLC2 should be configured as the Slave with different settings. Ensure correct Baud Rate, Parity, Modbus Role, and Slave ID configurations.
Answer: - Some common troubleshooting steps include verifying Modbus address settings, checking cable connections, ensuring proper termination, confirming correct communication module settings, and checking for any hardware issues.
Answer: - In addition to trying different Modbus address variations, you can double-check the configuration of both PLCs, verify the physical connections, review the Modbus communication protocol setup, and consider checking for any software or firmware updates that may address known issues.
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