Bit Memory adressing limit for Siemens CPU

[TurpoUrpo]

Less execution time, smaller program, does not modify currently open DB, common use between s5/s7

In order, valid if scantime is problem, i dont see benefit here, why would it matter?, s5 is burden of old, and should not affect how program is done now, if there is better way to do.

 

[KalleOlsen]

some instructions clear accu2 when executed in plcsim but work like documented in real plc (ofc).

Heeey, I didn't know that. Do you mind telling which?
Kalle

 

[TurpoUrpo]

Heeey, I didn't know that. Do you mind telling which?
Kalle

Atleast these. I remember reading that the reason is that plc sim works always like four accu cpu (if its that, then you can easily think what are affected instructions).

 

[Bratt]

There are a chapter in the online help called
Differences from a "real" PLC


One of the thinks stated

S7-PLCSIM supports four accumulators (like an S7-400 CPU).
In certain special cases, a program in S7-PLCSIM (with four accumulators)
can behave differently from the same program running on an S7-300 CPU, (with only two accumulators).

 

[KalleOlsen]

Atleast these. I remember reading that the reason is that plc sim works always like four accu cpu (if its that, then you can easily think what are affected instructions).

Yes, of course. I thought you'd found some funny malfunctions.

Kalle

 

[falgunvasava]

If you check in Simatic Manager--->PLC---> module information---->Performance data
you will see that PLCSIM would show the maximum possible ranges.
The Actual PLC supported ranges will be shown only when we connect to actual PLC.

 

[userxyz]

Thanks

Thanks,
very useful information !

If you check in Simatic Manager--->PLC---> module information---->Performance data
you will see that PLCSIM would show the maximum possible ranges.
The Actual PLC supported ranges will be shown only when we connect to actual PLC.

 

[Jeff23spl]

i like to keep the M not retentive and DB rententive so i can use M for sequence that need reset when powered down etc...

Using DB is some kind of limitless and when you work with few copy of the same thing in a project, you can copy it very easily by using 1 DB per device and just change the device number at DB name