Slaves not detected in profibus network of simatic 400 station

Dear Expert,

We are having 90 slaves in a Profibus network. Controlled by 443-5 EXT CP card as master.

And, my AS is Simatic 417-4 CPU.

Initially, I added all the slaves in the Profibus network with unique slave IDs. The local configuration also has been done in the right manner at the field.

When I monitor the connected device in Hardware configuration online, initially all were absent.

Then, we connected only one field device in the network. It was detected.

All these slaves are in IMCC feeders. Respectively TesysT (Schneider) and Danfoss Drive.

So, when we connect all the devices from the first feeder it was connected. But, if we connect the second feeder devices a couple of device from the first feeder gone offline.

Then, if we connect next to 15 th slaves, the entire slave is gone offline.

What will be the problem ???, we verified the Wiring connections, Continuity. It’s okay.

Then, All the slave is wired using 485 (2-wire) terminal connectors. It’s not the Siemens Profibus connector.

Then, My CPU won’t go to stop mode since we have respective OB call in the program. Also, CPU property assignment.

And, when I monitor the CP card Diagnostics, I was able to see some slaves IDs which was not connected in Online.

How do I can bring all these slaves online???

Kindly provide your suggestions. I will be thankful.

Here are some photos in detail.

Sanakiyen

Then, All the slave is wired using 485 (2-wire) terminal connectors. It’s not the Siemens Profibus connector.

???

Kindly provide your suggestions. I will be thankful.

Here are some photos in detail.

 Hello sanakyen;

You have diagnostic information on both of your CP 343-5 modules and ob your CPU, along with many of your slaves.

This is often linked with hardware problems on the bus, and especially with termination resistors. Lost (or unpowered) terminations will cause this type of problem.

Please give us more information on the terminal connectors you are using, make and model or datasheets if you can. Somehow my intuition is pointing to them as a source of these disturbances. And tell us what cable (make and part number) you are using to connect the slaves to the DP masters.

We will look at more details of your bus ( data transmission  speed, length of segments, number of slaves per segment...) if the need arises.

Hope this helps, 

Daniel Chartier 

Dear Daniel Chartier,

First of all thanking you so much.

Really, I was expected that you would replay to my post soon. Hats off to your dedication.

By the way,

i) We are using Siemens Profibus cable to connect the slaves.

ii) My initial point starting from CP card. it's connected using "Siemens Profibus connector".

And, since its outward, I have connected it from "A2, B2" terminals. and the end termination is in off.

When I turn it ON none of the slaves are detected. 

iii) All the field devices (slaves) are connected using RS 485 terminal. The wiring type is unusual here.

People have directly cut the Profibus cable. And, Connected the Green terminal with the Positive and the Red terminal with the Negative port of slaves.

From there they have made the parallel loop to the next slave. It's going up to the end.

iv) We are also using "Siemens repeater" -6ES7 972-0AA02-0XA0

S C-H8C67020

Totally we are having 3 repeaters in the network. Almost after every 30 slaves, we have placed the repeater.

 The Inlet is connected in A1, B1. And, we have taken the output from A2, B2. 

The mode is in ON condition. But, the S1, S2 termination are in off.

if I turn it ON, slaves are showing BUS fault. (Red LED indication).

v) All the Slaves are configured as "Automatic" for Transmission speed. There are no choices in local configuration of slaves.

I will upload the Photocopy and Hand sketch soon to give some more information clearly.

Hello Sanakyen;

I have checked the forum today and did not find the extra documents you were to provide, so here are some partial answers to your questions, with the information I have. Use the attachment for sources, the different images are not necessarily in the order of your questions.

- Point ii:  Look at attachment picture no 3: with a single cable you should connect to terminal A1-B1 of the connector, and set the termination to ON. This image and other relevant information can be seen in the following manual for Profibus Networks; it dates from 2001 but the information is still very useful:

https://support.industry.siemens.com/cs/at/en/view/1971286

- Point iii: Refer to picture no 1. The Red cable corresponds to the Positive (P) connection, the Green cable is the (N) connection. As stated in image 4, please check that all connections repect the continuous color coding, with Profibus connectors and with terminals; it requires a coninuity check between all Profibus connections, which may take time but will remove any doubt.

- Point iv: Whenever you use a repeater, it is to isolate/retransmit on 2 Profibus segments. Each segment must be terminated at each end, which means you have to learn to setup the termination switches on the repeater correctly. In the case you describe, A1-B1 (segment S1) to A2-B2 (segment S2), both termination switches S1 and S2 must be ON; see the attachment, image 2, and the termination of the end-point of the segment must also be ON (so the segment is correctly terminated at both ends). Examine image 2 in the attachment.

The Mode switch (inset between the switches S1 and s2 on the repeater) disconnects segments S1 and s2; it must be OFF if you want both segments to communicate.

- Point v: all Profibus slaves should take their bus speed reference from the master, unless the master determines that one or more of the slaves are not able to follow at the automatic speed (Profibus-PA slaves, for example). Then the master will set the speed for all slaves at the lower boundary limited by this slave's GSD file.

Hope this helps,

Daniel Chartier

Dear Daniel Chartier,

Thank you for your detailed response,

Actually, Sorry I couldn't add some documents since I was engaged.

Then, Whatever you have described in the Point number II, III, IV is the truth.

As initially, I followed that way. but, there was no response from the field.

Then, Just I tried some other way. In the end, I wondered there was a couple of slaves detected.

So, Finally, I have made the changes as what you have described. Now, We connected one more Siemens Repeater just after the first 15 nodes.

And, I have attached some image copies. Consist of

i) Slave Wiring detail, (For Danfoss Drive and Tesys T Motor controller)

ii) Profibus connector connection,

iii) CP card Diagnostic Report,

iv) Configured Profibus Network Speed.

v) Hand sketch Outline diagram of the Profibus network.

Kindly have a look at it.

Now, The first 15 slaves are detected. But, the rest of them not responding.

Also, I looked at the CP card Diagnostic. The Profibus speed was changed into lower boundary limit as what you informed in the point no V.

So, Kindly suggest me what speed should I configure now. How do I can go forward?

Hello Sanakyen;

I have been studying the documents you provided, and at this time i find no apparent fault in your design.

But you still have problems on site.And your diagnostics do point out a configuration error that blocks the functions of the network. For example:

Event 22 of 23: Event ID 16# F9C1:0203 Module database invalid.Internal cause: 14 External error, Incoming event 12:00:00.000 AM 01/01/1994(Coding: 16# F9C1 0203 0200 0000 1400 0000)

Event 23 of 23: Event ID 16# F9C1:0301 No valid configuration data found.OMS error code: 14 External error, Incoming event 12:00:00.000 AM 01/01/1994(Coding: 16# F9C1 0301 0100 0000 1400 1400)

So we have to look at where the installation deviates from the design, before looking to Product Support for help.

We would need one additional document if you please: a schematic of the network, showing the relative position of your master, slaves, repeaters, activated terminations and statuses. Especially trying to understand what groups of slaves fail, and does the failure relate to the position of a particular repeater.

If this is the case, we need to validate the consistency of the cables leading to that repeater, and terminations on the repeater, on the preceding and following group of slaves.

Hope this helps,

Daniel Chartier

Hello Daniel Chartier,

Thank you for your replay.

I will send you the schematic diagram. I have to prepare for it.

Meanwhile can you please tell me, Is it possible to set the BUS speed always constant?

Can we stop the CPU getting into lower boundary speed when some of the slaves are not detected?

Hello Sanakiyen;

I do not now of a way to programmatically change or limit the bus speed for a Profibus network, it is a matter of configuration. It must be loaded to the master's properties before it becomes active and that requires a reset of the master. 

By the way, would you or anyone near you have access to a Profibus tester of some kind, such as the Amprolizer software from Siemens? You would need a computer running Win XP and a CP 5611 to run the software, but once installed it would help analyze the trafic on the bus and detect connection faults that were undetected.

Procentec, Softing and other providers also have interesting options in that field.

Hope this helps,

Daniel Chartier

Hello Daniel Chartier,

Thank you for your replay,

As you told we are setting the BUS transmission speed in the Master network property.

But, there is no such kind of things to hold the master speed in same speed when does the slaves some of the goes to offline.

I will tell you the status. 

And, Yes, As you told we have raised inquiry to receive the Profibus tester.

We will see what will be the solution.

Dear Daniel Chartier,

So Finally, My problem was solved.

The Issue solved by considering two things. 

1. Unpowered Termination resister. It Happened due to Directly connecting the red, green terminals on Tesys T device RS 485 port using Ferrules.

2. The Ferrule created the loss of continuity to the next node at some places.

Thank you for all your suggestion.

All of our slaves connected with AS online, Now.