Hi,

Does anyone has experience of faulty BK3150 or any other Beckhoff Profibus coupler? In fact, I think there is an issue with this coupler. When we use a new one, after a while (ca. 6 months) it breaks without any explicit reason. By buying a new one everything works fine for a while, and again problem happens. All the wiring and connection were checked several times. Does anyone has same experience?

Thanks

 

We have several machines (about a dozen or so) that use the BK3150 to an S7-300 via Profibus. Some have been running for almost 5 years or so with no issues whatsoever.

 

What are the environmental conditions?

- Temperature
- Humidity
- Chemical exposure?
- Enclosure rating (IP65,NEMA 4X, etc...)
- Power line noise/Surge protection?
- Vibration?

 

Hi,

We have had issues with WAGO 750 Couplers in the past. These two companies have very similar hardware. You may need to check the configuration of the Couplers in relation to the I/O modules attached to the unit. The SI never really used these couplers and did not configure the attached I/O with the correct Isolation blocks between AIs, AOs, DIs, and DOs. We had problem with the couplers failing until I checked the configuration of the different nodes. Once the Power blocks and Isolation blocks where installed, we never have frequent failures again. The couplers would fail, but only after a power surge due to indirect lightning strikes.

Hope it helps.

Robert J. Dusza, Jr., COP
Project & Technical Support Manager
Manchester Water & Sewer Dept.

 

I have seen "mysterious" failures with several brands of profibus coupler. They tend to coincide with differences in ground potential, systems with floating power supplies and other situations that take the pins outside their common mode voltage limits. I have seen crappy IDC connectors render a system pretty much useless, only fixed by replacing them all with screw terminals. A very skeptical examination of the cabling and grounding has been known to remedy problems that have been mysterious for years. RS485 is very robust, but at MHz speeds everything needs to be right. With a DSO, a bad link will look like a bad link.

And check the terminators, it is not at all unusual for an extra one or two to be switched on, that's tough on the drivers.

Regards
cww

 

All the mentioned environmental conditions are in good situation except power line. In fact, I think the issue comes from power line but I'm not sure about it. There is sudden power failure and surge sometimes in main power line. Do you have any good document about the protection and good grounding for power line? And if the issue comes from power line ,why just Profibus coupler is sensitive to that?