Greetings, I am utilizing an IM153 as Decentral Peripherie with Profibus connection, configured as a slave with the address N° 2. Whenever there is a communication issue between the Master PLC and the IM153, error codes #38C4 and #39C4 appear. When troubleshooting, I download the PLC's diagnostic buffer for further analysis. The diagnostic buffer for module plc_carbo_02 [CPU 315-2 DP] shows hardware details such as Component Version 6ES7 315-2AG10-0AB0 with Firmware V 2.6.6 and Boot Loader A 0.21.0. The error #38C4 indicates a Decentralized periphery issue with the DP slave at device number 4, while error #39C4 points to a Decentralized I/O device failure at the same device. These events suggest a recurring cycle of connection and disconnection. Your assistance in resolving this issue would be greatly appreciated.
The OB86 error code is commonly caused by a DP slave device suddenly disappearing or reappearing. This issue can be attributed to various factors such as noise interference, defects, poor grounding, or inadequate shielding. A potential solution is to inspect and replace the connectors at the DP slave or the preceding connector if they are found to be faulty. Additionally, ensure that the shield is properly connected to the ground (GND) in the connector to prevent future occurrences of the error code.
Hello adrirock1141! I'm curious about the baud rate you're currently utilizing and the length of your PROFIBUS line. Are you using Siemens or a different standard PROFIBUS cable, or perhaps a general-purpose cable? Also, are you using standard PROFIBUS connectors with both connectors at each end and the termination switch turned on? Additionally, what is the cycle time of your PLC program and approximately how much IO data are you receiving from field devices overall?
Greetings Alfredo, The Profibus Line spans approximately 30 meters and is equipped with 4 addresses. It utilizes Siemens Profibus cable and operates at a speed of 1.5 Mbps. The setup includes: - Number 1 PLC (On resistor) - Number 2 IM153 (device with the fault, Off resistor) - Number 3 HMI (working normally Off resistor) - Number 4 HMI (Working Normally On Resistor) The distance between the PLC and IM153 is minimal, around 1.5 meters. The HMIs are situated about 29 meters away but are functioning correctly. The IM153 serves as an expansion of the PLC, facilitating the exchange of a larger amount of data compared to the HMIs.
It appears that the issue may not be related to the bus, as the baud rate (1.5MBaud) and cable length are within standard limits and all media and termination are correct. The problem seems to be isolated to the IM153 DP field devices, while the other devices are functioning properly. This suggests there may be a problem with the IM153 module itself. Have any recent maintenance been performed on this device? Have you attempted to power off the device, disconnect the modules, and check for any contact issues or clean the bus contacts? Are there any discrete output modules that could be causing a short circuit? Have you checked the diagnostics buffer for the field device? Profibus provides valuable diagnostics information, and the IM153 datasheet should offer guidance on interpreting this data. The network configuration in the Simatic 7 software will indicate where to access the diagnostics data.
It is highly probable that the IM153 is the main suspect in this situation.
It sounds like you're dealing with a frustrating issue there! The recurring connection and disconnection you're experiencing could be due to a few factors — not just hardware but also configuration settings. I'd suggest double-checking the wiring and ensuring the power supply to the IM153 is stable. Additionally, it might be worth revisiting the DP settings on both the master PLC and the IM153 to make sure everything lines up correctly. Have you tried a different address for the slave to rule out any address conflicts? Sometimes a fresh configuration can clear up underlying issues. Good luck!
It sounds like you're dealing with a pretty tricky communication issue! Since the errors #38C4 and #39C4 both relate to the decentralized periphery and point to device number 4, I would suggest checking the physical connections and ensuring that the wiring is intact—sometimes a loose connection can be the culprit. Additionally, reviewing the configuration settings of the IM153 and the setup of the Profibus network might reveal some discrepancies. Have you tried swapping out the IM153 with another slave module or even testing it in a different configuration to rule out hardware failures? That could help isolate the problem further!
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Answer: - Error code 38C4 indicates a Decentralized periphery issue with the DP slave at a specific device number, while error 39C4 points to a Decentralized I/O device failure at the same device.
Answer: - One way to troubleshoot these errors is by downloading the PLC's diagnostic buffer for further analysis. Analyzing the diagnostic buffer can provide insights into the hardware details and help identify the root cause of the communication issues.
Answer: - Resolving the recurring cycle of connection and disconnection may involve checking the physical connections, ensuring proper configuration settings for the DP slave at device number 4, and addressing any Decentralized I/O device failures at that device. Additionally, updating firmware versions and bootloader software could also help resolve the issue.
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