Greetings experts,

I am currently using AP Library V9.1.

Can an EM Instance acquire a VlvL (Valve - Large) block, like an EPH instance acquiring an EM Instance?

I noticed there are parameters in VlvL that are Batch related (BatchID, BatchName, StepNo, etc.)

and parameters that are Acquire related (AcquireId, AcRequest, AcPriority, etc.)

If possible, I want to utilize the above parameters to configure an EM to acquire a VlvL block. However no AP Library manual even has the above parameters in the VlvL section.

PCS 7 Compendium Part C only has contents about EPH acquiring EM and I have no idea how to utilize those parameters.

Help understanding how to use those parameters to make an EM acquire a VlvL (if it is indeed possible) would be greatly appreciated.

Or link to a manual containing above inquiry would be appreciated as well.

Thank you.

Hi BYForever,

sadly that's not possible. CMTs are directly linked to exactly one EMT. When I want to use a CMT as shared resource I assign it to an own EMT. This EMT then can be used by other EMTs and EPHTs via the acquire logic. With this approach also all Batch relevant data will be transferred to the CMT.

Thank you for the reply Trivial.

If I understood correctly, one CMT can only be acquired by one EMT?

And impossible for multiple instances of that CMT to be each acquired by different instances of EMTs?

Also, information about what manual I can find this information would be appreciated.

To be more specific: The term acquire would be wrong for CMTs. It is always linked to exactly one EMT/EPHT via block contacts. Acquire only applies to EMT/EMT or EPHT/EMT combinations. It uses some kind of arbitration logic (or multiplexer) called MARC. The attached picture should clarify the difference between both approaches (see chapter 10.5.5 of compendium C, sadly also in the english documents the text in the picture are German).

As documentation I recommend to read the Compendium C. If you have access to the Intranet/Extranet (for example as Siemens partner) I especially recommend this document: Engineering and automation of batch processes with PCS 7 along ISA-88 models

Depending on your needs there are also other options to share a CMT, like ShrdResS from the APL.

I see. Acquiring applies only to EPHT/EMT or EMT/EMT.

So then what is the purpose of these variables in VlvL or VlvAnL block?

They seem to be related to acquiring.

(Input)

(Output)

I guess I'll have to leave those variables out of the equation for now, then.

Is there a manual that contains information about each interface variable of an EMT/EPHT?

I can't seem to find it anywhere.

Edit: I found it, guess I wasn't looking hard enough. It's called SFC for SIMATIC S7 (V10.0)