Doing the "impossible" with S7 DP comms.

[PLucas]

Ok Jesper

Here I am trying to make up for my mistake this morning...

After I wrote my last post, I then attempted to use SFB15 for the comms, still to no avail, so I changed the 300 configuration to say it was networked on profibus (DP/FMS) and tried to establish comms, all to no avail.

As it stands at the moment, the way I have been trying is a failure, I will now see if I can establish comms with the 315 by dropping a S7 300 station into the 412 project, set it up as per configuration and try again, the way you wanted to try this.

I was rather hoping that I could establish comms using the 'other station' configuration, as you can with ethernet, that way you would not need to touch the 'other PLC' at all, you would only change your master PLC.

Getting a bit late to carry on today.. (nearly time to go home!), I will have a few beers tonight and ponder this problem, ready to try again on Monday.

In the mean time, if you have a project setup and ready to go, email it to me and I can load it straight in, that will save both of us writing the same projects out.

S7412-2DP - 6ES7 412-2XG00-0AB0 V1.2
S7315-2DP - 6ES7 315-2AG10-0AB0 V2.0.8

We will solve this one way or another

Paul

 

[JesperMP]

SFB15 "PUT" is for configured connections, so it wont work with standalone programs.

Anyway, I am qurious as to how you got it to work with X_PUT before.
You are right that the online help says "for MPI only":

Address parameter "destination ID." This contains the MPI address of the communication partner. You configured this with STEP 7." This

Did you have an MPI network setup with both S7-300 and S7-400 connected ?
If it is possible to use something else than the MPI port, then there should be a parameter to specify which port. As there isnt, then it definitely looks like "MPI only".

I will have at least one beer myself, and will send a thought to "dear ol' Paul" while I have it.

I notice that "cartman" cannot resist ANY chance to show off his graphics skills.

 

[PLucas]

Did you have an MPI network setup with both S7-300 and S7-400 connected ?

The answer to that is no, I did have them connected initially via MPI for ease of programming and ethernet for comms, but when I had a play this morning I definately removed the connecting lead from the MPI port and connected the DP ports together. The ethernet was still connected, but I doubt if that came into play. But, to ensure the ethernet comms had no effect, I removed the 343 and 443 from the racks when I set them up at lunch time.

If I hadn't of written over the projects that I used this morning, I could have reloaded them and tried it again, but alas they are gone forever, never to return to these shores.

I will dig out all the notes I have on S7 networking, (I done the course a couple of years and a bit ago), maybe I could find something useful in them. As I said before, you can definately do this via ethernet, you do not change anything on the 'remote' PLC just the master. I am pretty sure in that case you use X_PUT and X_GET. Anyway, I will do some light reading over the weekend and see what I can come up with.

I notice that "cartman" cannot resist ANY chance to show off his graphics skills.

That's Eric for ya. He's certainly a bit of an artist!

Paul

 

[JesperMP]

In the mean time I have been brainstorming a little.

If this X_PUT/X_GET does NOT work out, then I think there is another very different possibility:

Set up the S7-400 as the DP master and all others as DP slaves.
It should then be possible to use FC1 DP_SEND to send data to each slave. Unfortunately the help text only mentions CPs, not built-in DP ports.

And if THAT does not work out either, then we can try the scheme with "pseudo-integrated" projects.

Cheers !

 

[PLucas]

Jesper

This post will add more to the confusion/debate

the picture attached shows that I did have comms initially via profibus at 16:46 and 15 seconds this afternoon, but, because I had the bf LED flashing on the 315 at the time I didn't notice it, as I shut everything down for the weekend, I noticed that I still had the VAT table open and on line, but as the RTC on the 400 is about 15 minutes fast, I had changed the configuration again by then... DOH!!

I will have to leave this till after the weekend, when I can start on it again with a fresh and clear mind.. it's been a long week.

Paul

 

[The Dark Knight]

Ever messed around with MultiProject?

Step 7 v5.3 has a multiproject feature. All of your projects can be combined into one massive one. Make all of your CPU be on the same DP subnet and they can be setup to communicate with one another.

 

[CT782]

I remember hearing about that in a sales seminar. It's a software package called iMAP I believe. Basically your programs in each machine will look like an FB and you just link the IO between machines virtually. Not sure if it's included in 5.3 or extra.

 

[The Dark Knight]

What I am referring to is part of Step 7. In Simatic Manager, go to File -> New Multiproject. Name the multiproject, then import your existing projects. When you go into Netpro, you will be able to link the PLC's via DP, IE, MPI, etc.

 

[PLucas]

It's a software package called iMAP I believe.

That rings a bell with me, I have heard of iMAP, but I am not sure if we have a copy of it at work. I don't think that it is part of V5.3 because I am pretty sure that that is the version I use at work, I have v5.2 at home.

I will have to look into the 'multi-project' option, but my understanding of what Jesper is trying to do is that he wants to read and write to a PLC that he hasn't 'configured' or programmed, it arrives already running on a machine and rather than alter this PLC in any way, he wants to be able to communicate with it, as I have already stated this is very much possible with ethernet comms.

That was what I was trying to achieve on Friday, but using profibus rather than ethernet.

Maybe, this isn't possible and Jesper will have to resort to altering the partner PLC, but it's good fun to try and I might learn something in the meantime as I very rarely use multiple PLC projects, in fact all of the projects I have done are with stand alone PLC's, some with a TP screen.

Does iMAP allow you to communicate with a PLC that comes pre-programmed and configured?

Paul

 

[JesperMP]

Yes, the problem is that the various parts of the projects comes from several vendors.
And they will not or can not let their programs be included into one big project.

The other "constraint" is that I want to utilise the allready built-in DP ports that all the CPUs have (typically S7-315 2DP and S7-414 2DP). (Yeah, I am a "Cheapskate").

It is not impossible to make changes to the various programs. But it is impossible or near-impossible to integrate all projects into one.

I am hypotethising what could explain why Paul could communicate via X_PUT in the beginning:
Maybe Paul had set up connections between the S7-400 and the S7-300 some time before, maybe he had used the same connection ID numbers as their Profibus node numbers.
Then at some time he uses PUT (rather than X_PUT) and specifies the Profibus number as the ID, coincidentally specifying the right connection number.
And presto, the communication works.
Then when Paul makes a complete reset, he also deletes the connections. So the next time it does not work.

 

[PLucas]

Jesper

Your Hypothosis could well be near the truth, i.e previous connections were still 'resident', but I did not have them linked via MPI for inter PLC comms, the only inter PLC comms I was previously using was via the 343 and 443, hence the removal of these units from the racks. I am pretty damn sure that I removed the MPI cable and plugged it into the DP ports when I started this on Friday morning, so at that time there was no MPI link at all. That still doesn't explain why the 412 'wrote' to the 315 late Friday evening, I can't explain that either.

I will have another play around today at lunchtime (13:00hrs), from what I read over the wekend, this is possible via a DP CP card, but not via the built in DP port. I will have to try and dig that info back up to confirm this.

In the meantime, if there is anything you want me to try, then post it here and I will give it a go.

Paul

 

[JesperMP]

Morning Paul,

the possibility that I pondered about would require a DP connection, not a MPI connection. So if you had a cable between the two DP ports then this could be the explanation.

I think that it is NOT possible to use X-PUT, because the documentation says so, and because you have to specify an MPI address and not a "connection ID".

So, there are two ways as I see it now:

1. Master-to-master comms.
1a: Setup connections between the two CPUs over the DP port in an integrated project. Both DP ports are masters. Program PUT to write from S7-400 to S7-300.

1b: If that works OK, then use the existing project to create two new projects. Reset both CPUs and download the two separate projects.
For the S7-400 in Netpro, highlight the S7-400 only and download the connections.

1c: If thats works OK, then try to add an "unspecified connection" for the S7-400 and see if that can connect to the S7-300.

1d: If that works OK, then try to manipulate the connection parameters and/or the Profibus until the comms fails.

2. Master-slave comms.
Look in Siemens FAQ database and search for entry ID 1020634.
It explains how to setup an S7-315 2DP as a DP slave, and how to use I_PUT and I_GET to communicate data. The projects do not have to be integrated into each other.

 

[PLucas]

Update!!

Ok, Jesper

Here's what we have so far:-

One project setup with both CPU's in that project and networked via Profibus DP , only the 400 has a configured connection in Netpro, there is no connections for the 315.

Using SFB15 (PUT), we have the 400 writing to the 315, no problem. So that is your step 1 complete, we have, master to master comms with the 315 as passive.

I will now try and get your second step completed, I am not sure if I will get time today to do that as I have some proper work to do that will benefit Thamesport not the rest of the world!

I not sure if I should admit this or not... but today I noticed that on the configuration of SFB15, I had the ADDR_1 and SD_1 any pointers reversed, in other words I was trying to read from an area that didn't exist on the 412, although the area I was writing to existed on the 315. I put this down to tiredness and lack of concentration on my part on Friday.. Nice and fresh on a Monday morning and I spot my mistakes..

Paul

P.S So far I have only 'PUT' data in the 315, would you like me to 'GET' some data?

 

[JesperMP]

So far I have only 'PUT' data in the 315, would you like me to 'GET' some data?

Not really. If PUT works, then I believe GET will also.
The interesting part is when you make separate projects, and when you try an "unspecified connection". Now THAT will be something.

 

[PLucas]

A bit more completed

Jesper

Here's what I done next:-

Shut down the project used above and deleted the 315 and the MMC. Opened up a new project with just the 315 in it, configured completely from scratch, I didn't copy and paste anything from what I done previously, had this networked as profibus, but with nothing 'hanging' off the network, I left the addresses as default. Downloaded this configuration to the 315.

Stop, started the 412 and monitored the DB I created in the 315, there was the data being written to the 315.

That is halfway to doing what you wanted in step 1b, apart from the fact that I didn't recreate the 412 from scratch, I'm not sure that this will accomplish anything as the configuration would still be the same as I would have to hang a 'dummy 300' on the 412's profibus to setup the local connection to use SFB14 with.

That is all I have time for today, or at least the next few hours, I might be able to get some more done later, if not it will be tomorrow morning.

Paul