Hello Sir

we have a running machine in which siemens network are installed.

Drive shown fault no. F1910 & F7220 from last 15-20 days.

We read manual and try all remedy according to the manual,

Profibus Network are connected in B/W IM-ET 200,

From Out side of profibus connector drives (07 No's) are connected & other in side of connector 2 No's HMI are installed.

Resistance 220 ohm of profibus connector when Switched ON at connector

Cable resistance 0.9 OHM

Earthing value Below 1 OHM of each connectors

The network working ok but any time the fault occur.

The network shown in attached photo...

Please help me for the same its very important for me

Thank you

humperdoo

Clean all connectors, check if they are fixed firmly, check the cable, if you have access to the plc sw reduce profibus speed and/or adjust profibus parameters and upload hw, maybe install active terminators on both ends of the profibus cable. That's about all i can think of.

Thanks sir, for giving your responce

1- I replace all connectors with new one

2- Replace New cable

3- Just now i'll try to reduce baud rate speed then i'll reply soon

petr_sipor

just a note

the minimum cable length between two participants is 1m

sir,

i attached the picture of panel. Please have a look and confirm that is it ok or not.

we use minimum length 600 mm. It will work or not?

Looking at the photo it would be useful to pull those profibus cables away from what i assume are transformers/chokes under the drives. An electromagnetic field so close to the pb cable can affect it.

I've done even shorter cables between drives and no problems. But if all else fails, you can always try.

Going for the lowest speed 187kbps might also help.

There is also a parameter that can compensate short bus faults P2047, set it to something like 1 second on the affected drives and see.

Hello sir,

I pull away profibus cable from Chowk

I did baud rate at 187 kbps but i get alarm of BF ( i.e. A1920 Profibus : Cyclic connection interrupted ) in IM-ET 200S and 3 no's drive other 4 no's drive are ok, no fault.

so i put baud rate same as earlier due to machine running for production.

Thanks to all experts for helping.

Sir, Machine in production but still problem occur, so i decided to purchase a new CU unit for testing all 7 No's CU, I'll replace one by one to test CU's,

Today i received a new CU unit,

May be the fault in CU unit so i'll test the CU's then i'll give my feedback

Hello Every one,

We purchase New CU 1 Nos and replace one by one on each drive but still problem is same.

Fault F7220 - Control by PLC missing 

What it's mean?

Is that control signal by profibus or control IO's from PLC to drive?

Can any one please explain?

Thank you sir for giving your feedback

Sir, We don't have the oscilloscope or profibus analyzer. or we don't have here a big maintenance team, i am only the engineer present in hole production plant and i am just beginner in siemens system ( Small size of industry ).

So any other option to analyze this problem...!

Hello Every one

At last 15 days earlier we replace all new DP connectors (10 No's) so machine run smoothly for 4-5 days, after that same fault occur so we purchase new CU unit 1 no's and check one by one in each drive (7 no's),

but from last evening drive show fault again and again in every 5 to 10 min F7220 & 1920, so at night till 2 am i was checked and found 3 connectors resistance open and 400-500 ohm,

I analysis the fault and found that my Profibus connectors resistance disturbed,

2 No's connector resistance - found open circuit

1 No's connector resistance - found 400-600 ohm variable

I replace that 3 connectors but i need to know why resistance disturbed or open.

Can any buddy tell, why this happen?

please help for the same

Thanks

Sir,

That's my network current status

Hello every one

Finally i replace all drive CU from profibus to profinet to resolve this fault 

F1910 & F7220.

We dont have any better option to improve our production

Thanks every one to helping out

Hi all!

I will add information about error 1910.

The equipment has been working for 13 years. The S400 controller with CU320-2 DP are used. The error appeared 3-4 times per a week. After viewing the controller error logs it became clear that the entire PROFIBUS network was falling off. The problem was at the power supply module 220VAC/24VDC. I guess that it was a short-term voltage drop. It powers signal repeaters and terminators.

The machine has been working for 10 days and I hope that this problem doesnt happen again.

hi,

One more thing. the converter should not be used as an end user on the profibus. Because if it is switched off, the termination on the profibus will be disconnected. so the end element should always be powered.