Profibus Error #38C4 and #39C4 Help!!!!

[adrirock1141]

Hello everyone , im using a IM153 as Decentral Peripherie, it uses profibus and it is a slave with the adress N° 2

everytime there is a problem with the comunication between the Master PLC and the IM153, it appers the error #38C4 and the error #39C4, I download the buffer of the PLC, i will copy the buffer down

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Module diagnostic buffer plc_carbo_02 [CPU 315-2 DP]


Reference / designation Component Version
6ES7 315-2AG10-0AB0 Hardware 7
- - - Firmware V 2.6.6
Firmware Upgrade Firmware Upgrade Boot Loader A 0.21.0


Rack: 0
Slot: 2


Serial number: S C-W7UU21382008


1 out of 10;
Event ID: 16# 38C4
Decentralized periphery: return team
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/16/2024 09:17:14,089


2 out of 10;
Event ID: 16# 39C4
Decentralized I/O: Device Failure
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/16/2024 09:17:13.288


3 out of 10;
Event ID: 16# 38C4
Decentralized periphery: return team
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 23:32:11,062


4 out of 10;
Event ID: 16# 39C4
Decentralized I/O: Device Failure
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 23:32:10.266


5 out of 10;
Event ID: 16# 38C4
Decentralized periphery: return team
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 22:17:58.114


6 out of 10;
Event ID: 16# 39C4
Decentralized I/O: Device Failure
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 22:17:57.321


7 out of 10;
Event ID: 16# 38C4
Decentralized periphery: return team
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 18:35:52.629


8 out of 10;
Event ID: 16# 39C4
Decentralized I/O: Device Failure
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 18:35:51.833


9 out of 10;
Event ID: 16# 38C4
Decentralized periphery: return team
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 10:57:19,661


10 out of 10;
Event ID: 16# 39C4
Decentralized I/O: Device Failure
Address of the affected DP slave: device number: 4
DP Master System ID: 1
Log base address of DP slave: Input address: 2046
Log base address from DP master: Input address: 2047
Requested OB: Rack fault OB (OB 86)
Priority: 26
01/15/2024 10:57:18.825
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Its Looks like there is a cyclic connection and desconection all the time.

Please somebody helpme

 

[JesperMP]

OB86 is triggered when a DP slave disappears or reappears.
There can be many possible causes. Noise, defects, bad grounding, improper shielding.
A good candidate is that the connector at the DP slave or the connector before that is defective. Change these connectors and be careful about connecting the shield to the GND in the connector.

 

[AlfredoQuintero]

adrirock1141, hi.
What is the baud rate you are using?
How long is the PROFIBUS line?
Are you using Siemens or other standard PROFIBUS cable? Or is it a general purpose cable?
Are you using standard PROFIBUS connectors with the two connectors at both ends with the termination switch in the ON position?
What is the cycle of the PLC program and how much IO data are you getting in total from the field devices (the input to the PLC and the output from the PLC to the field devices, roughly?

 

[adrirock1141]

Hello Alfredo
The Profibus Line is like 30 meters long, it have 4 Adresses, its using siemens profibus cable, a speed of 1.5 Mbs
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 very small, like 1.5 meters, the Hmi's are like 29 meters away, but they are working fine.
About the data, the IM153 its working as a expansion of the plc, so its exchanging more data, than the Hmi's

 

[AlfredoQuintero]

OK, so it seems the problem is not bus related because the baud rate (1.5MBaud) and the cable length are complying with the standard and you have correct media and and termination, and your program is seeing this problem only for the IM153 DP field devices whereas the two other devices work normally.
I think there may be an issue with the IM153 itself. Has anybody recently done maintenance on this device?
Did you try powering off the device and disconnect the different modules, check whether there was a contact issue between the IM153 modules, maybe clean the internal bus contacts?
Are you using some discrete output modules, could there be a short?
Can you read the diagnostics buffer for this field device? Profibus has diagnostics information that can be very useful, and the IM153 datasheet should provide information for the interpretation of the diagnostics data.
The network configuration in the Simatic 7 software should tell you where this diagnostics data can be viewed.

 

[JesperMP]

+1 that the most likely culprit is the IM153.