Good morning,

I am trying to establish communication to transfer data from a S7-200 (224XP) to a S7-300 CPU (CPU 317-2 PN/DP).

I am using a Profibus cable to connect one another and I am trying to implement the S7 basic communication with SFC67 and SFC68 (XGET / XPUT).

The communication and the transfer of data is working if I call the block XGET only ONCE. If I try to call the function twice, to read a different range of bytes I get an error code (80C0: the specified connection is being used by another job). I could call the block once but it is limited to 76 bytes and the data to be read on the S7-200 is between VW1 and VW2360.

Do you guys have any idea what is wrong here ? Attached is a screenshot of the program used to call the function SFC67 twice.

Thank you

GB

Hello GBraillon,

I made some test (in this case only with X_GET), but in SCL between 2x S7-300 via MPI and working perfectly. Simply I was preparing 2 DBs on Server PLC, each has struct of one BYTE, filled with different value. On Client S7-300 prepared selectable driving of 2x SFC67 via int memory value (via value I start call each SFC67 as BUSY of each one is false), each SFC67 has REQ=true and also CONT=true, only has different lookup to DBs numbers. From begining I was think to make that communication quick as possible without some needed Timer driving, so when I got BUSY=false on one GET, select driving value for next GET call. This system working pretty quickly and didn't recognize any big CPU cycle time value. Maybe important for you can be change S7 Basic communication settings value on your CPU properties to your needed value.

 I tried with both but I had the same results

UMENCHO

Why the CONT is TRUE?

 Did you try to get data from the same DB ? and from different range of bytes ?

Duris_I

Hello GBraillon,

I made some test (in this case only with X_GET), but in SCL between 2x S7-300 via MPI and working perfectly. Simply I was preparing 2 DBs on Server PLC, each has struct of one BYTE, filled with different value. On Client S7-300 prepared selectable driving of 2x SFC67 via int memory value (via value I start call each SFC67 as BUSY of each one is false), each SFC67 has REQ=true and also CONT=true, only has different lookup to DBs numbers. From begining I was think to make that communication quick as possible without some needed Timer driving, so when I got BUSY=false on one GET, select driving value for next GET call. This system working pretty quickly and didn't recognize any big CPU cycle time value. Maybe important for you can be change S7 Basic communication settings value on your CPU properties to your needed value.

Hello,

yes, read from same DB in external PLC but from different offset, f.ex. one GET with

P#DB12.DBX0.0 BYTE 10

and next X_GET f.ex.

P#DB12.DBX13.0 BYTE 10

No problem, also for destination collect area this data are putted to right offset also to same destination DB with same schema.

I was preparing 2 simple X_GET FCs (STL), each with different Pointer like on begining and call them after each has executed (conditioned via BUSY and simple byte value) cyclically again and again.

Update: better explanation, simply now I can run also both FCs with X_GET (each with different read offset of data) on same time without restrictions. My upper mentioned example I run with my conditions, step by step not at one time. I want only show you that some possibilities are everytime available. You can make test with each X_GET disconnected after job execution, then you can run next one probably.

It is working fine now. It looks like two blocks SFC67 cannot be called at the same time even though the request boolean is not active on both.

I added a counter to enable one block or the other and create a cycle.

Thanks for your help !

G