How to call a transaction property in another transaction?

[Former Member]

Hi,

I am receiving a SAP UID value into a BLS-1 transaction property. The BLS-1 invokes some processing in the OPC Server which subsequently invokes another BLS-2 to send the data back to SAP. My question is how to access the SAP UID value sent to BLS-1 from BLS-2?

Regards,

Chanti.

[Former Member · Accepted solution]

You could dump the UID in a Que..ue if you can determine some common key between the transactions, like a tag name or something. Synchronization might be an issue though.

[Former Member · Accepted solution]

You are right Chritian. Although the 'Transaction Call' in association with the 'Tag Name' thing may work, synchronization is going to be an issue. Particularly, when I will have more tags with probably the same names. Any other ideas?

Chanti.

[sidnooradarsh · Accepted solution]

Hi Chanti,

I am not sure how complex or feasible it is to send the SAP UID to OPC, store it in some variable or something within OPC and send it to BLS-2 while invoking from OPC along with other data.

Regards,

Adarsh

[Former Member · Accepted solution]

Chanti,

what about using the built-in Simulator for storing a value or a csv string?

More about using custom values in Simulators are described in [CurrentWrite with Simulator Tag does not save value|http://forums.sdn.sap.com/click.jspa?searchID=33627599&messageID=7136259].

Michael

[Former Member · Accepted solution]

I am afraid, that is not an option 'coz it may require significant changes made to the PLC programs.

Chanti.

[Former Member · Accepted solution]

Could you be more specific about your idea? We are using KEPware, not the in-built simulator.

Chanti.

[Former Member · Accepted solution]

You can use the MII Simulator to store values that can be read/written by any BLT.

We tested the functionality described in the thread above to use it as a flag if a BLT is already running to prevent parallel execution of the same BLT.

In your case you can store the SAP UID value in a predefined Tag of the Simulator in BLT 1 and read out the value in BLT 2. This way you do not need an external DB to store values.

Michael

[Former Member · Accepted solution]

I suspect there are going to be sync issues. Particularly, when you are dealing with number of tags simultaneously. What do you think?

Chanti.

[Former Member · Accepted solution]

Is there a limit on the number of simulator tags that one can create?

Chanti.

[jcgood25]

Transaction property scope is only IN / OUT of a transaction, so you will need to define one in BLS-2 and link it in.