Read float parameters from a SINAMICS in a S7-1200

Hello,

I have a similar problem when trying to read float parameters from a SINAMICS module in a S7-1200 PLC. For example, for register r55501 I can read in STARTER the value of 9.51V but in PZD I have a completely different value. I don't have any scaling for this parameter. I saw the answer above and tried in S7-1200 to multiply the PZD value with the 0x4000 0000 (value 2 in float) and still it stil wasn't correct. 

Sorry for the rookie question, but do you have a suggestion how can this operation be applied in my case?

Thank you,

Oana

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Split from S120 PZD Send of r63 is incorrect.

oana.chenaru

[snip]  for register r55501 [snip]

 I don't have any scaling for this parameter.[snip]

 Did not found r55501. Please specify correct drive & parameter number.

PISCEAN 2010

 

oana.chenaru

[snip]  for register r55501 [snip]

 I don't have any scaling for this parameter.[snip]

 Did not found r55501. Please specify correct drive & parameter number.

 It's the manual found here:

https://support.industry.siemens.com/cs/attachments/99007204/DCP_List_Manual_LH21_0516_eng.pdf?download=true

Thank you,

Oana

There must always be a reference. I see that this info is missing in the manual obviously. But all BiCo parameters in SINAMICS in float format are normalized to a reference value when being interconnected. I am not familiar with SINAMICS DCP but I guess there is something like parameter p2001 (maybe hidden). 

In the PLC you must calculate:

real value = received value / 16384 * reference value 

oana.chenaru

 

PISCEAN 2010

 

oana.chenaru

[snip]  for register r55501 [snip]

 I don't have any scaling for this parameter.[snip]

 Did not found r55501. Please specify correct drive & parameter number.

 It's the manual found here:

https://support.industry.siemens.com/cs/attachments/99007204/DCP_List_Manual_LH21_0516_eng.pdf?download=true

Thank you,

Oana

Hello,

r55501 is actual voltage value in % of side 1 power unit, so if you want to send r55501 value to PLC say PZD word 1, set p2051[1] = r55501. So if r55501 = 100%, PLC will receive 16384 Dec or 4000 Hex. If you see 9.51 means at PLC will receive 1558 Dec or 380 Hex. r55501 is referenced to voltage value in r50071 i.e. rated voltage of device according to technical data.  

HTH.

I tried what you recommended and it still doesn't diplay ok. I assume it might be becuse my value is float (double word) and #4000 is single word. 

Do you now this equivalent?

Thank you,

Oana

It is only a double word in case you connect it to 2 PZDs (e.g. PZD 8+9 or so). 

Then the equivalent is 4000 0000 hex for 100%

RB91

It is only a double word in case you connect it to 2 PZDs (e.g. PZD 8+9 or so). 

Then the equivalent is 4000 0000 hex for 100%

Thank you very much. It worked like this.

We first converted the received value to float and also converted this constant value to float. So the final formula which provided the correct value was:

real value = float (received DW value) / float(0x4000 0000)* reference value

I think you mean DriveData := DWord_TO_REAL(received DW value) / DWord_TO_REAL(16#4000_0000) * Reference_Value;

You might consider creating some user constants, like:
Drive100PC : Word = 16#4000
Drive100PC_DW : DWord = 16#4000_0000
D1_Speed_RefValue : Real = 3600 (rpm)
... 

Then anytime you need a reference value or to scale a value from a drive, all the data is there in one place.  New project, or motor swap, edit the user constants that change, compile and download.  If you want to get fancy, at drive power up, request the reference values via asynchronous parameter request (SINA_PARA block by Siemens).  Then as long as the drive is configured correctly, the PLC program will not change if a motor is swapped with different reference data.

oana.chenaru

RB91

It is only a double word in case you connect it to 2 PZDs (e.g. PZD 8+9 or so). 

Then the equivalent is 4000 0000 hex for 100%

Thank you very much. It worked like this.

We first converted the received value to float and also converted this constant value to float. So the final formula which provided the correct value was:

real value = float (received DW value) / float(0x4000 0000)* reference value