Read onboard AI

Hello Experts,

We have Sinamics G120 series VFD with CU240E-2PN control units and S7-1500 PLC and we question; is it possible to send raw count of onboard analog input of VFD to PLC through Profinet by any means? 

I am aware that onboard analog input meant for speed setpoint feed but is there any way to send raw count to PLC by any telegram through VFD?

Thanks in advance.

Regards,

Parag Zope.

You can transfer the metered value of the AI to the PLC,

If you have Tel352, you may change one of the send values in Tel 352 in the configuration of the send data (communication>transmit direction)

If you have Tel1, or an other small telegram, you first have to expand the telegram in the PLCs telegram configuration.

Have a look on this forum thread too:  https://support.industry.siemens.com/tf/ww/en/posts/g120-actual-current-telegram-352/221683/?page=0&pageSize=10#post879886 

miami

You can transfer the metered value of the AI to the PLC,

If you have Tel352, you mach change one of the send values in Tel 352 in the configuration of the send data (communication>transmit direction)

If you have Tel1 or an other small telegram you first have to expand the telegram in the PLCs telegram configuration.

Have a look on this forum thread too:  https://support.industry.siemens.com/tf/ww/en/posts/g120-actual-current-telegram-352/221683/?page=0&pageSize=10#post879886 

Hello,

Thank you for the reply @miami. I will try to explain in brief what we intended to do,

There are two mixing tanks with agitator having VFD control and need to check minimum weight of the tanks (measured using differential pressure) to interlock agitator. So if we connect transducer directly to AI of VFD and send raw count to PLC where we gonna scale it and display on HMI as well. Would this work?

I know we can simply add analog input module with PLC rack but the issue is we need to integrate 18 more tanks with VFD control for agitator in future and as of now we are doing just two of them. So every time we have to lay cables, add analog module, punch hole in panel etc to add each VFD afterwards. 

To resolve this we asked if there is any possibility to read AI through VFD and send it to PLC for scaling.

Thanks in advance.

Regards,

Parag Zope.

Hi,

yes it is possible.

You can even do the scaling within the drive itself.

What you get then is a signal in percentage which you can send to the PLC via cyclic telegram. As Miami already said you will need to adapt one of the standard telegrams to select the AI as value to be transmitted to the PLC. This is simply done by interconnecting the AI parameter to the wanted PZD (transmitting word) of the telegram.

See the attached screenshot.

The value that you will receive in the PLC will be normalized to 100% = 4000hex = 16384dec. -200% = FFFFhex and +200% = 7FFFhex.

Hello Experts,

As per our previous discussion I tried expanding telegram 1 by 2 words and commission drive using standard telegram 1 only. Where I find p2051 were locked out and i could not able to assign AI0 value to it. 

Can you suggest which telegram should I use? If any other telegram to be used other than standard telegram 1 which FC/FB to be used to control drive from PLC? 

Previously I used standard telegram 1 with SINA_SPEED block. But if i change telegram SINA_SPEED wont work i guess?

Thanks in advance.

Regards,

Parag Zope.

Hi,

you can work on with telegram 1 and SINA_SPEED FB if you want.

You should expand the telegram by adding additional setpoint/actual data -> see my screenshot.

Then this additional data will get its own Hardware ID (also see screenshot).

From the PLC you can read the data with the GETIO block. (see screenshot).

RB91

Hi,

you can work on with telegram 1 and SINA_SPEED FB if you want.

You should expand the telegram by adding additional setpoint/actual data -> see my screenshot.

Then this additional data will get its own Hardware ID (also see screenshot).

From the PLC you can read the data with the GETIO block. (see screenshot).

 Thank you for the reply. I understand how to read value in PLC now but what connections should I do at drive side? By which parameter drive would send data to extended address?

Thanks in advance.

Regards,

Parag.

See my previous screenshot for that!

Connections of values to be send from the drive to the PLC are set in p2051[x]. Index 0 and Index 1 are for standard telegram 1. The next indexes are for your additional data. Connect e.g. the output parameter of analogue input (I think r755) to p2051[2].

RB91

See my previous screenshot for that!

Connections of values to be send from the drive to the PLC are set in p2051[x]. Index 0 and Index 1 are for standard telegram 1. The next indexes are for your additional data. Connect e.g. the output parameter of analogue input (I think r755) to p2051[2].

 Hi,

I tried the same but with standard telegram used; parameter p2051 got locked. ( see attached )

Any advice?

Regards,

Parag.

Hi,

try to change p922 to "999 free BiCo"