Help troubleshooting Modicon M340 Problem

[Aazim Raza]

Hey all,

I am having an issue concerning the Modicon System Responsible for the operation of our Generator System. (Particularly Dresser-Rand SFGLD 560).

The Problem is with the analog Output Module BMXAMO0410, which unexpectedly Malfunctions and trips the Generators. (one Channel of this module is responsible for Maintaining and controlling Voltage via AvR).

The output of All 4 channels in the module stops and only 1 green status Led is stable on the Module.

Then we have to Power Recycle the Rack to normalize the module. Although, the problem again arises after almost every other week.

We also replaced the Analog Output Module, and the problem vanished. But after 3 to 4 months of operation, the same issue was raised again and we are clueless.

We also accessed the debug option from Unity Pro for the module and it stated as

External fault - Power Supply Fault
Internal Fault - Module Unserviceable
Other Fault - Application Fault

After power recycling, these faults gets reset.

Can anyone help me with the problem??

 

[chud]

I would 1st have a look at the wiring. Are the outputs fused before it leaves the panel? If yes are the fuses sized correctly? How far is it between the card and the final device? Looks to me like there is some short circuit or too much load on a channel pull the whole card down

 

[parky]

Never used Modicon but in a few PLC's I have had these types of fault, the usual causes are wiring (i.e. loose connections or broken wire internal to the outer coating so would make if moved). Poor contacts on the backplane/ contacts or dry joints. Had exactly what you described (SLC500) & a clean of the backplane connectors & re-solder all the connectors cured the problem probably worth looking at.

 

[Aazim Raza]

I would 1st have a look at the wiring. Are the outputs fused before it leaves the panel? If yes are the fuses sized correctly? How far is it between the card and the final device? Looks to me like there is some short circuit or too much load on a channel pull the whole card down

The wiring is oK. And no fused installed in between. The distance is short almost 50 to 60 Meters. Did isulation testing and loop testing of the cable. Nothing found. Verified the cable through out. No damage in wire also.

 

[Aazim Raza]

Never used Modicon but in a few PLC's I have had these types of fault, the usual causes are wiring (i.e. loose connections or broken wire internal to the outer coating so would make if moved). Poor contacts on the backplane/ contacts or dry joints. Had exactly what you described (SLC500) & a clean of the backplane connectors & re-solder all the connectors cured the problem probably worth looking at.

I am in a similar doubt that the issue is linked to the backplane. But the programming software is also indicating for Faulty Power Supply. Anyways, today I have replaced the Power Supply and Backplane. And took the machine into operation. Let's hope for the best.

 

[jorge?07]

Problem with PLC M340

Good Day, I have an issue between an M340 PLC and a PRA 0100. The problem is as follows: I have a communication link between the PLC and the PRA controlling a process. However, at a certain point, the entire process stops without any faults in either the PLC or the PRA. After monitoring, the following occurs: an input module flashes at a certain moment and then the process halts. This observed detail is akin to pressing the stop button, which is not the case. I suspect it may be a backplane issue or a faulty module