Step7 - where is the Ethernet address defined?

[RMA]

I'm involved in troubleshooting a production line at present and it turns out that the data being sent to the data logging/statistics PC is incorrect. I'm pretty sure that the data is being sent via Ethernet by the CP343 using AG-SEND, but in order to be sure I'd like to check that the Ethernet address is indeed that of the PC. Where can I find this info? In Netconfig each of the PLCs has three undefined partner connections, but in the communications FBs I can't find anything looking remotely like an Ethernet address.

Cheers

Roy

 

[PLucas]

Roy

I assume that you want to confirm that the IP address of the PC is the same as the define one in the S7 project.

What type of connection has been declared in Netpro?

You did say that there are 'undefined' partner connections, but I am sure that you still have to confirm what type the connection is I.E S7 connection, ISO on TCP, TCP etc. Depending on the type of connection, you normally have to state the IP address of the partner station, this IP address should show up in the connection bars at the bottom of the Netpro screen when the relevant CPU is highlighted. I take it this is not happening.

A screen shot might be helpful.

Paul

 

[RMA]

Hi Paul,

yes, that's what I want to do. Unfortunately, I won't be able to do a screen dump until tomorrow, but in Netconfig the undefined partner connections are defined as TCP connections, but I couldn't persuade it to show me an Ethernet address. Presumably because the partner is defined as being undefined, it's address box is empty.

Cheers

Roy

 

[PLucas]

Roy

When I attempt to add an unspecified TCP connection to a CPU (via CP343) in Netpro, I get the following pop up....

As you can see, I am asked to provide an IP address of the unspecified partner, this convinces me that the IP address of the remote partner is available........ somewhere.

Paul

 

[RMA]

I tried that out this morning with the same results. Unfortunately, if I right click on one of the existing connections and open up the properties window, the remote connection address is empty.

I don't really have enough Ethernet knowledge for this! Is it possible that instead of sending the data to a specific Ethernet address, the data is just being openly broadcast to anybody who wants to hear it, on the network?

Is there any way I can check if this is the case?

Cheers

Roy

 

[Bratt]

If you use Iso-On-Tcp there is no need to enter the ip adress of the remote partner if the the other partner is the one that makes the active connection. Only the Tcap needs to be configured. If you mark the cpu and press the button Activate/Deactivate connection status you can se if the connection is up or down. Also if you check the connection properties in netpro in the general informations tab there you can see the block parameters to be used with the ag_send/recive call for this connection.

Its possible to send brodcast or multicast messages but then the connection needs to be configured as brodcast or multicast. If the connection is unspecified only one pc or plc can be the remtote partner.

Its also possible to se the partners ipadress if the connection is up. Check under special diagnostics for the relevant cp card. Check the tab Connections--> Iso on tcp. You also have a useful ping option under the menu options.

 

[JesperMP]

Interesting. You learn something new every day.

This part of the help text for an unspecified connection on ISn_TCP:

An unspecified connection must be specified in the New dialog. The connection establishment is then passive, the remote IP address is 0.0.0.0 and the remote TSAP is empty, in other words, they are irrelevant for the Ethernet CP. When the connection is established, any partner is accepted (partner = connection name).
With connections that are not managed in an S7 project, you can enter the IP and TSAP (complete address) of the partner here.
If the connection remains unspecified, any communication partner can establish a connection to this station based on the station address.

 

[JesperMP]

Hmm. upon reading the whole thread, I see that Roy has a TCP connection, not ISn_TCP.

The help text is a bit different:

Connection to an "other station" in another project
You can specify the remote IP address and the port for any destination station. The destination station can be within or outside the current STEP 7 project.

It doesnt say explicitly that you can leave the parameters unspecified, but the word "can" sort of says that it is OK.
There is no TSAP to specify, only IP and port.

 

[RMA]

Those last three posts are interesting, Jesper and Bratt, but I think I need a little more time to digest them before I can turn them into something useful. I'll have a further look at this over the weekend and then see where I get to on Monday.

I'm about to depart on my 4 - 5 hour drive back home, so thanks for the help so far and

Cheers, have a good weekend

Roy

 

[Bratt]

Sorry i dident se that it was a tcp connection i just saw Iso on tcp somewhere and my mind automatically set on iso on tcp. But same goes for tcp connections you only have to adress the local port remote fields can be empty. This gives you the advantage that if the it department needs to change the ip or the port on their side you never have to reprogram the plc. And you can have diffrent clients connecting to the plc but only one at a time.

Also here you can see the partners ipadress in the special diagnostics for the cp card if the connection is up under connections-->tcp

 

[PLucas]

Sorry i dident se that it was a tcp connection i just saw Iso on tcp somewhere and my mind automatically set on iso on tcp.

Bratt,

That was me, I mentioned ISO on TCP when I asked Roy what type of connection it was.

The rest of your reply makes interesting reading, that was something I didn't know (then again there's plenty I don't know!). I had no means of testing out what I posted above, if I could of tested it, maybe I might have discovered the fact that the remote partner does not have to be specified, then again, maybe I wouldn't have.

Paul

 

[RMA]

The situation has now resolved itself and it turns out that the PC concerned was the only one on the network.

Lot's of useful information turned up though, for which many thanks!

Cheers

Roy

 

[JesperMP]

So, it actually works like we think it does ?

The IP address is not specified in the PLC's connection list.
The PC establishes the connection.

HOw is the connection setup on the PC ?

 

[pouch]

I used a CP 343- 1 to communicate to an OS running winCC. The IP addressing was set up in the hardware configuration as follows:

CP 343-1
Object Properties
- General
- Properties

and from there the IP address can be set of the CPU and the Operator Station.

This has to be done off line although you can verify the setting on line. I did not need to use AG Send/Receive, these functions are used for profibus comms.

Regards

Pouch