S7-1200's Transfer Data

504bloke

Lifetime Supporting Member
Join Date
Jan 2005
Location
Down South
Posts
2,721
Hi All

Been absent for a while :)

Have a small project, 2 x S7-1200's and one KTP700 Basic panel - On profinet

Without using GET/PUT commands is there a way to transfer a tag between the two PLC's using the HMI - the HMI has no scripting so thats out

I must be missing something as I cant see how to do it
 
Neved did it this way, but you could try this:

You can use the "Value change" event on a variable from one Plc, and as event function use "SetTag" and set the variable in one Plc to the variable the other Plc.
As trigger variable you could use an integer which is incremented every 10 seconds or so in one Plc. Or use the variable which has to be transmitted itself as trigger, but sometimes you want to transmit the value from time to time eben when it not has changed.
 
I forgot: set the "Acquisition mode" at the trigger variable and the variable of which the value has to be read to "Cyclic continuous".
 
You can use TSEND_C to squirt data out of a PLC and TRCV_C to receive it, but you would have to do your own error correction. Or a more roundabout way would be to use Modbus TCP master and slave. I tend to use Put and Get because I like a simple life.
 
Why the limitation on PUT and GET? That seems like the solution for two PLC's to communicate.

Another way, that I used extensively for one to many communication is with UDP multicasts. I did this on a 1500 a couple of weeks back, so it should work on the 1200's.
One thing to bear in mind is that you can only send something like 240 or 480 (forgot which) bytes.
 
One PLC and HMI is supplied by me - all on the same profinet network as a German machine, the other PLC is a German companies - the customer won't let me alter the code in the German companies PLC in any way as otherwise the warranty is invalidated according to the germans (its a new machine), so Get / Put and altering their PLC code is out of the question, hence the question
 
GET and PUT will work (if enabled already) without altering their PLC code. Any other option will not as it will require the matching receiving/transmitting function between CPUs.

I assume, obviously, that the other machine has some tags prepared to receive communication and to send information back to your machine.
 
Neved did it this way, but you could try this:

You can use the "Value change" event on a variable from one Plc, and as event function use "SetTag" and set the variable in one Plc to the variable the other Plc.
As trigger variable you could use an integer which is incremented every 10 seconds or so in one Plc. Or use the variable which has to be transmitted itself as trigger, but sometimes you want to transmit the value from time to time eben when it not has changed.

Thanks Thomas, Just had a look and that looks possible so will try when next on site later this week
 
GET and PUT will work (if enabled already) without altering their PLC code. Any other option will not as it will require the matching receiving/transmitting function between CPUs.

I assume, obviously, that the other machine has some tags prepared to receive communication and to send information back to your machine.

Its not enabled
 
I love it when the customer is ignorant about control systems and in charge of projects... At this point, the solution you are trying and may find will be patchy and definitely not straight forward.

Explaining that the best option for the customer is to call the German company and tell them they need to put in a DB with PUT/GET access to do X and Y is probably your best bet at the moment.
 
I love it when the customer is ignorant about control systems and in charge of projects... At this point, the solution you are trying and may find will be patchy and definitely not straight forward.

Explaining that the best option for the customer is to call the German company and tell them they need to put in a DB with PUT/GET access to do X and Y is probably your best bet at the moment.

Done that, Customer paid a lot of money and now the Germans want a fortune to do an hours work and edit the code - So customer is a bit bitter - I keep saying you should have had me do the whole job :)

The German code is convoluted as well, 4 FB's/FC's nested and numerous (100's) of DBs for a relatively simple machine with 8 motors (DOL) on it !

They even have a special DB for "Always ON" and "Always OFF" bits rather than using the siemens standard bits !

There screen is good as well, so much on it you look at it and go cross eyed!
 
What are you trying to achieve ?
The supplier wont change the program, but you want to make some kind of interfacing between this machine and another machine.
How is this possible without involving the designers of both machines ?

Anyway, if you know which addresses in the S7-1200 to use, then Thomas V2's suggestion should work since unless it has been blocked by a password, as HMI can access the PLC variables by default.
PUT/GET requires that it is enabled in both PLCs.
 
The German code is convoluted as well, 4 FB's/FC's nested and numerous (100's) of DBs for a relatively simple machine with 8 motors (DOL) on it !
I didn't see the code, but any chance that they have a one fits all program?
I had that in the past and it seemed convoluted until you understood that changing bits in a couple of DB's configured the machine.
One in particular was a control station that had every single functionality configurable from DB's. The code made no sense whatsoever, until you read the configuration manual.

They even have a special DB for "Always ON" and "Always OFF" bits rather than using the siemens standard bits !
I can sort of understand this... is the code in SCL? You have to remember that Siemens guidelines tell you never to use M bits and they then put this functionality in M bits.
 

Similar Topics

Hello all, I am working on a project utilizing an s7-1200 cpu and Tia Portal v17. I currently have an external PCB with some sensors on it (and...
Replies
1
Views
705
Hi, I have a Pilz m BO which hardware is all set up. I am just beginning to set up the transfer of data between. I have added the transfer areas...
Replies
0
Views
2,172
Does anyone knows how to transfer the data of a data block to another? the DBs have exactly the same structure. I'm using TIA 10.5. Thanks in...
Replies
5
Views
5,266
so after a previous thread about the panelview 1200. I figured everything out that I needed to get working with it. I've got the RIO discrete...
Replies
5
Views
1,561
Hi, At one of my sites contractors have failed to supply a backup of our TP1200 Comfort HMI. I was going to try and carryout a backtransfer in...
Replies
10
Views
4,969
Back
Top Bottom