I made many working PUT/GET connections and I have a simple question about PUT/GET.

CPUs are S7-1200 or S7-300, software is TIA Portal v16+ or Simatic Manager 5.5+.

I have one CPU which should collect information from other CPUs. One GET instruction is sufficient for transfer (no need for more than 160 bytes data).

May I call all PUT/GET functions at once, not waiting one by one to be finished ? PUT/GET instance blocks are separated, not shared.

C-3PO

I made many working PUT/GET connections and I have a simple question about PUT/GET.

CPUs are S7-1200 or S7-300, software is TIA Portal v16+ or Simatic Manager 5.5+.

I have one CPU which should collect information from other CPUs. One GET instruction is sufficient for transfer (no need for more than 160 bytes data).

May I call all PUT/GET functions at once, not waiting one by one to be finished ? PUT/GET instance blocks are separated, not shared.

Triggering all the PUT/GET at the same time should not be a problem.

The PUT/GET blocks can run independent from one another. The communication port's internal management system should schedule each task as they arrive. The messages will be queued.

A problem comes when attempting to use more resources than what is available. You are using static connections, so the compiler will warn you if there is issues.

Saturating the message queue is the next problem area. The PUT/GET instruction will however put out a fault status if there is a problem there. This can therefor be detected.

The next and more likely problem is triggering a PUT/GET before the previous transaction was completed. Also having multiple resources link to the same DB area, is an issue.

Your thoughts?

qwazee

 

C-3PO

I made many working PUT/GET connections and I have a simple question about PUT/GET.

CPUs are S7-1200 or S7-300, software is TIA Portal v16+ or Simatic Manager 5.5+.

I have one CPU which should collect information from other CPUs. One GET instruction is sufficient for transfer (no need for more than 160 bytes data).

May I call all PUT/GET functions at once, not waiting one by one to be finished ? PUT/GET instance blocks are separated, not shared.

Triggering all the PUT/GET at the same time should not be a problem.

The PUT/GET blocks can run independent from one another. The communication port's internal management system should schedule each task as they arrive. The messages will be queued.

A problem comes when attempting to use more resources than what is available. You are using static connections, so the compiler will warn you if there is issues.

Saturating the message queue is the next problem area. The PUT/GET instruction will however put out a fault status if there is a problem there. This can therefor be detected.

The next and more likely problem is triggering a PUT/GET before the previous transaction was completed. Also having multiple resources link to the same DB area, is an issue.

Your thoughts?

Yes, I was in delusion that every GET/PUT should wait for termination (NDR, ERROR) nevertheless is it for different CPUs or not. Until I saw a working (?) example with several GETs which addresses different S7-300. Maybe I was confused with this How do you configure and program an S7 connection and the “PUT” and “GET” instructions for data transfer between two S7 CPUs?, although it is a different case.

Anyway, your post clarified what I suspected.