DP CP coupler data transfer and communication

Hello team, I am trying to set up a communication between a Siemens S71500 and a Beckhoff system. We have decided to us a siemens DP DP coupler since the Beckhoff system has a profibus network present.

I have configured the DP coupler on the Siemens part and used same config on the Beckhoff side. (All pictures attached). I also created a Db structure to collect data from and to the DP input and output sides.

My question is, how can I do data transfer from a DB to the DP coupler output side and also transfer data from the Input side to a DB in my project. The DB created has "optimized access". This I can change if it is necessary.

What instructions can I use to move these data from and to the DP coupler's input and output areas?

I am using a Siemens TIA V16 update 4.

I would also appreciate if there are any sample programs I can follow in TIA.

Hello oluwasedago;

The setup of a DP/DP coupler is all a question of hardware configuration, so there is nothing special about using it with TIA Portal. But there are a few things you must ensure if you want to make this work:

- What are the special features of input/output addressing with the DP/DP coupler?

https://support.industry.siemens.com/cs/ww/en/view/22327981

First, the DP/DP coupler is designed as a 2-sided slave allowing I/O exchanges between 2 Profibus-DP masters. (it has 2 different Profibus interfaces, one connected to each master's Profbus network). Is the module you are using for the Beckhoff PLC a  Profibus-DP master?

Second, a DP/DP coupler exchanges data from input and output addresses, not from DB memory. You must copy the DB registers that you want to send to the Beckhoff PLC to the outout (%Q) addresses of the Siemens PLC (from the DB) and write the input (%I) addreses received from the Beckhoff PLC to the DB regsters of the Siemens PLC in your user program. 

Third, the I/O of the DP/DP coupler configuration in the Siemens PLC must match, line per line, the Beckhoff configuration , in size and datatype, except that input and output data must be reversed, See the screenshot below, showind an example configuration in 2 masters. Whatever is input to the Siemens PLC becomes output to the Beckhoff PLC, whatever is output from the Siemens CPU becomes input to the Beckhoff master.

Lastly: Siemens makes a distinction on Profibus data that is consisent over unit, and consistent over total. Consistent over total is the equialent of a telegram, the data, no matter how many bytes long, is transfered all together. I do not recommend this for the Beckhoff CPU, simply confgure the DP/DP coupler data as consistent over unit (or without consustency) and transfer the I/Os to the Beckhoff registers as you need them.

Hope this helps,

Daniel Chartier

 Hello dchartier,

Thank you very much for this explanation. You have cleared a lot of doubts from my mind and I understand better now.

I decided to test my program on the S71500 with a S7300 using same config and if everything works fine, I can move over to configuring the Beckhoff. So, now I am working with the S71500 TIA V16 connected to a S7300 Step 7 V5.6.

I have been able to configure the system as it should be and there is NO SF error with respect to the Hardware config. In fact, I can send bits of data from one PLC to the other.

However, I do not know how to move these data from DP coupler input or output to the DB.

Could you please give me an instruction to use?

I tried the DPWR_DAT and DPRD_DAT over the consistent areas, and no data transmission even when there is no error on the S71500 side but error exists on the S7300 side.

Do you suggest that I should not use the Input and Output consistent types in the hardware config when connecting to the Beckhoff? I did not understand this part.

I used DP input and outputs as bytes, how can I map DB to these areas or vice versa?

Thank you very much

dchartier

Hello oluwasedago;

The setup of a DP/DP coupler is all a question of hardware configuration, so there is nothing special about using it with TIA Portal. But there are a few things you must ensure if you want to make this work:

- What are the special features of input/output addressing with the DP/DP coupler?

https://support.industry.siemens.com/cs/ww/en/view/22327981

First, the DP/DP coupler is designed as a 2-sided slave allowing I/O exchanges between 2 Profibus-DP masters. (it has 2 different Profibus interfaces, one connected to each master's Profbus network). Is the module you are using for the Beckhoff PLC a  Profibus-DP master?

Second, a DP/DP coupler exchanges data from input and output addresses, not from DB memory. You must copy the DB registers that you want to send to the Beckhoff PLC to the outout (%Q) addresses of the Siemens PLC (from the DB) and write the input (%I) addreses received from the Beckhoff PLC to the DB regsters of the Siemens PLC in your user program. 

Third, the I/O of the DP/DP coupler configuration in the Siemens PLC must match, line per line, the Beckhoff configuration , in size and datatype, except that input and output data must be reversed, See the screenshot below, showind an example configuration in 2 masters. Whatever is input to the Siemens PLC becomes output to the Beckhoff PLC, whatever is output from the Siemens CPU becomes input to the Beckhoff master.

Lastly: Siemens makes a distinction on Profibus data that is consisent over unit, and consistent over total. Consistent over total is the equialent of a telegram, the data, no matter how many bytes long, is transfered all together. I do not recommend this for the Beckhoff CPU, simply confgure the DP/DP coupler data as consistent over unit (or without consustency) and transfer the I/Os to the Beckhoff registers as you need them.

Hope this helps,

Daniel Chartier

 Hello Wizard and thank you for your reply,]I have tried to use the functions.

I am currently set up with a S71500 and S7300, because I want to test everything before connecting to the Beckhoff to be sure that the S71500 has everything correct. I do not get an error on the data transmission for S71500 and I get error for the S7300.

Could you please inform me on how I can send the input area of the DP coupler in BYTEs to a DB and also send a DB byte structure to the DP output area?

If I use just bits, I can get the data both ways, however, over the consistent data type, no data transfer happens.

Thank you very much.

Wizard

Hello,

Have you tried to use the functions: DPRD_DAT and DPWR_DAT

See online help for more information.

Best regards,

Wizard

Hello oluwasedago;

You do not show anywhere your final DPDP coupler configuratiion between the S7-1500 and the S7-300, so it will be easier to pretend that the example I showed you earlier as a screenshot represents the data you want to exchange through the DP/DP coupler.

If you open the screenshot and say Project 1 is the S7-1500, then Project 2 will be your S7-300. Look at line 3 of h configuration, 8 Bytes IN for the s7-1500 (addresses 3..6), 8 Bytes OUT for the S7-300 (addresses 0..3). Note that these are word-sized addresses, not bytes.

That line of the configuration means that the s7-300 will send 8 bytes (QB0 to QB8) to the S7-1500 (%QB3 to %QB10). The value in QB0 (S7-300) will be transfered to %QB3 or the S7-1500.

Consider these addresses as a mailbox. Where is the value of QB0 coming from, in the S7-300 program? You say it is a DB, so let's say DB10, in Byte 10. So when you are ready to transmit that value to the s7-1500, you program a MOVE instruction in the S7-300 to copy DB10,DBB10 to QB0, Then Profibus takes care to bring it to the S7-1500, in %QB3. What do you do with that value in the s7-1500? You copy %QB3 to the S7-1500 DB you have prepared for this purpose.

This is a very simple explanation of the mechanism used for data transfer to and from a DP/DP cupler. Depending on how your data is organised in your DB there are other instructions (BLK_MOV for example) that will allow the copy of multiple sequential bytes with a single instruction, making this a lot easier.

Hope this helps,

Daniel Chartier

 Good morning dchartier and thank you very much for this explanation.
I understand the concept very well now, i really appreciate. I also thought I attached the configuration image but I somehow missed it. I have attached it again alongside the DB structure.

If i understand your explanation, I should use IBx and QBx to address inputs and outputs respectively since i have used Bytes, if I had used Word, then it would be IWx or QWx...?

Also, your explanation talks about the data which were not consistent, how can I address the consistent ones?

The goal for me is to move each single data from every part of the PLC to a single DB and then move the DB as a whole to the DP coupler for the other PLC to access it.

You should have a better idea when you look at my DB structure perhaps.

I will proceed now as you have advised and inform you of nay progress later.

Could you show me how to program the BLK_MOV and does it work for the consistent part? I can also do away with the consistent bytes if it makes everything easier.

Thank you once again. I have attached the structure.

dchartier

Hello oluwasedago;

You do not show anywhere your final DPDP coupler configuratiion between the S7-1500 and the S7-300, so it will be easier to pretend that the example I showed you earlier as a screenshot represents the data you want to exchange through the DP/DP coupler.

If you open the screenshot and say Project 1 is the S7-1500, then Project 2 will be your S7-300. Look at line 3 of h configuration, 8 Bytes IN for the s7-1500 (addresses 3..6), 8 Bytes OUT for the S7-300 (addresses 0..3). Note that these are word-sized addresses, not bytes.

That line of the configuration means that the s7-300 will send 8 bytes (QB0 to QB8) to the S7-1500 (%QB3 to %QB10). The value in QB0 (S7-300) will be transfered to %QB3 or the S7-1500.

Consider these addresses as a mailbox. Where is the value of QB0 coming from, in the S7-300 program? You say it is a DB, so let's say DB10, in Byte 10. So when you are ready to transmit that value to the s7-1500, you program a MOVE instruction in the S7-300 to copy DB10,DBB10 to QB0, Then Profibus takes care to bring it to the S7-1500, in %QB3. What do you do with that value in the s7-1500? You copy %QB3 to the S7-1500 DB you have prepared for this purpose.

This is a very simple explanation of the mechanism used for data transfer to and from a DP/DP cupler. Depending on how your data is organised in your DB there are other instructions (BLK_MOV for example) that will allow the copy of multiple sequential bytes with a single instruction, making this a lot easier.

Hope this helps,

Daniel Chartier

 I Also noticed that my DP ID is the same for outputs and inputs for the S71300 while non shows on the S71500 side.

oluwasedago

 Good morning dchartier and thank you very much for this explanation.
I understand the concept very well now, i really appreciate. I also thought I attached the configuration image but I somehow missed it. I have attached it again alongside the DB structure.

If i understand your explanation, I should use IBx and QBx to address inputs and outputs respectively since i have used Bytes, if I had used Word, then it would be IWx or QWx...?

Also, your explanation talks about the data which were not consistent, how can I address the consistent ones?

The goal for me is to move each single data from every part of the PLC to a single DB and then move the DB as a whole to the DP coupler for the other PLC to access it.

You should have a better idea when you look at my DB structure perhaps.

I will proceed now as you have advised and inform you of nay progress later.

Could you show me how to program the BLK_MOV and does it work for the consistent part? I can also do away with the consistent bytes if it makes everything easier.

Thank you once again. I have attached the structure.

dchartier

Hello oluwasedago;

You do not show anywhere your final DPDP coupler configuratiion between the S7-1500 and the S7-300, so it will be easier to pretend that the example I showed you earlier as a screenshot represents the data you want to exchange through the DP/DP coupler.

If you open the screenshot and say Project 1 is the S7-1500, then Project 2 will be your S7-300. Look at line 3 of h configuration, 8 Bytes IN for the s7-1500 (addresses 3..6), 8 Bytes OUT for the S7-300 (addresses 0..3). Note that these are word-sized addresses, not bytes.

That line of the configuration means that the s7-300 will send 8 bytes (QB0 to QB8) to the S7-1500 (%QB3 to %QB10). The value in QB0 (S7-300) will be transfered to %QB3 or the S7-1500.

Consider these addresses as a mailbox. Where is the value of QB0 coming from, in the S7-300 program? You say it is a DB, so let's say DB10, in Byte 10. So when you are ready to transmit that value to the s7-1500, you program a MOVE instruction in the S7-300 to copy DB10,DBB10 to QB0, Then Profibus takes care to bring it to the S7-1500, in %QB3. What do you do with that value in the s7-1500? You copy %QB3 to the S7-1500 DB you have prepared for this purpose.

This is a very simple explanation of the mechanism used for data transfer to and from a DP/DP cupler. Depending on how your data is organised in your DB there are other instructions (BLK_MOV for example) that will allow the copy of multiple sequential bytes with a single instruction, making this a lot easier.

Hope this helps,

Daniel Chartier

 

Hello dchartier and Wizard,

Thank you very much for your explanations, they have really helped me.

I have been able to transfer data between the S71500 and S7300 ON the NON-CONSITENT parts of the DP coupler. I used the move function for both. Image attached. I also see data on both ends when I check the VAR table. So far, the BOOL data types match on both ends.

I changed the Db properties to be "Non Optimized"

Now my next questions are:

The main data that i will be transferring are mostly REAL data type, so I tried to load a random real data from S71500 to a %QW to go to the S7300. The data is displaying in form of 16#D262 instead of values like 0.23456. How can I do this?

1) How can I move data FROM and TO the DB which is constructed with a BYTE structure? Data types like INT, REAL etc? Writing and Picking BITS work fine.

2) The Consistent data transfer part doesn't work, can i do away with it and increase the NON-consistent data inputs and outputs OR it works better and if possible, how can I use it?

3) I have over 60 REAL data types to be moved from the S7300 into the S71500 and the configured Input and outputs are 64Bytes in size. Do i need to add more configuration to the hardware or there is a possibility to use this channel to do the transfer?

I know that a REAL datatype is 4 Bytes, which means I would need 4 X 60 = 240 Bytes of Input and output config in the HW. please am I correct?

Thank you very much!

 My Db structure is attached

oluwasedago

Hello dchartier and Wizard,

Thank you very much for your explanations, they have really helped me.

I have been able to transfer data between the S71500 and S7300 ON the NON-CONSITENT parts of the DP coupler. I used the move function for both. Image attached. I also see data on both ends when I check the VAR table. So far, the BOOL data types match on both ends.

I changed the Db properties to be "Non Optimized"

Now my next questions are:

The main data that i will be transferring are mostly REAL data type, so I tried to load a random real data from S71500 to a %QW to go to the S7300. The data is displaying in form of 16#D262 instead of values like 0.23456. How can I do this?

1) How can I move data FROM and TO the DB which is constructed with a BYTE structure? Data types like INT, REAL etc? Writing and Picking BITS work fine.

2) The Consistent data transfer part doesn't work, can i do away with it and increase the NON-consistent data inputs and outputs OR it works better and if possible, how can I use it?

3) I have over 60 REAL data types to be moved from the S7300 into the S71500 and the configured Input and outputs are 64Bytes in size. Do i need to add more configuration to the hardware or there is a possibility to use this channel to do the transfer?

I know that a REAL datatype is 4 Bytes, which means I would need 4 X 60 = 240 Bytes of Input and output config in the HW. please am I correct?

Thank you very much!