ET200S DI/DO module failure

[sanket_shete]

Hi,

We are having S7400 CPU, connected to ET200S modules. The system installed and commissioned in 2005-06.

5 S7400 CPU having nearly 20 ET200s stations connected to each CPU.

Since last couple of month we started getting problem of random failure of IO module in running plant with SF and BF fault on Interface Module which leads to stoppage. We are using 2DI 6ES7-131-4BB00-0AA0 and DO 6ES7-132-4BD00-0AA0 with interface module ET200S- 6ES7-151-1aa05-0AB0.

System becomes healthy and runs well after replacing faulty module

Though we are maintaining basic conditions like temperature of surrounding area around 25 to 28 deg, very less dust exposure.

What are things to check to predict/prevent the failures ?

Regards,

Sanket Shete

 

[azetou]

Hi,

First thing to check is quality of power supply.
second to check for radio interference if you installed any new device nearby.

azetou.

 

[jacoffey85]

I second checking the power supply. I had a similar instance where extra devices were added to a 24v system and ended up being too much for the PSU which caused us to eat up a few devices before we realized the PSU was too small.

 

[sanket_shete]

Hi,

Thanks for reply.

We have not added any devices or installed anything near by. Also whatever DI/DO module failure, they all have different power supplies.
(To tell you in brief we have 5 process with individual control system (not interconnected), every card failure was on different system (not on same power supply).

 

[jstolaruk]

Have you brought up this issue with Siemens?

 

[sanket_shete]

Yes,

Siemens Engineer visited, but found nothing wrong with installation or operating conditions.

We have sent the modules to siemens for failure analysis.

 

[JesperMP]

Earthing ?
Overvoltage from lightning strike ?
Corrosive gases ?

 

[antoine]

Hi,

A few years ago I had similar problem in similar place.

After a looooooooong search, we found that the problem was due to the installation of a high voltage transformer on site. That ground was not nonnected properly.

... just a guess ...

Antoine