Analogue input on ION7650 vs ION9000

[ArmandV]

Hi All,

We recently replaced a faulty ION7650 meter with an ION 9000 meter.
The ION 7650 meter was reading an analogue signal.

We therefore fitted the ION9000 meter with an analogue expansion card (METSEPM89M0024) to read the analogue input signal.

After the replacement of the meter. We compared the analogue input data of the ION 7650 vs the ION 9000 meter with Power Monitoring Expert. Please see the attached snippet.
It seems that the data has "shifted down" and is now recording in the vicinity of -6 to 5 units, where as on the ION 7650 meter it recorded in the vicinity of 0 - 10 units. 
The same settings applied to the Analog Input Module for the ION 7650 meter on Designer was applied to the Analog Input Module on the ION 9000.

I double checked the wiring and all seems fine and looks exactly the same as the ION 7650 meter. We do not have the optional shield terminal wired for A1 on the expansion card METSEPM89M0024, however this was also not wired on the ION 7650 meter.

Could incorrect polarity cause this issue?
Would wiring the optional shield terminal assist?
Any other suggestions?

Thanks you.
BR
Armand 

[Charles_Murison · Accepted solution]

Hello @ArmandV 

The first question I would have is did you try measuring the analog signal to the meter and compare to the meter readings? Is your signal 0-20 mA, 4-20mA other?

First step would be to determine if the meter is reporting the signal it is receiving correctly. This determines if meter needs to be investigated or the source of the signal. 

Regards,

Charles

[ArmandV]

Hi @Charles_Murison ,

Thank you for the quick feedback.

We are using 4-20mA analog signal. 

I will work with the client to verify the analog signal from the source and get back to you.

Regards,
Armand 

[Charles_Murison]

Hello @ArmandV ,

Any luck verifying the signal to the meter?

Regards,

Charles

[ArmandV · Accepted solution]

Hi @Charles_Murison ,

Thank you for following up and the continued support.

Yesterday we found out that the flow meter outputting the analog signal was changed a year or so back. 

Also to my knowledge I was certain that the old signal from the old flow meter wired to the ION 7650 meter was a 4-20 mA signal, however checking the datasheets of the ION 7650 meter analog cards, it looks like they only support 0 to 20mA and 0-1mA signals.

I set the ION 9000s analog input to 0-20 mA yesterday, and the signal looks much better now, it is shifted back upwards, and has not went into the negative since then.
I am still waiting for the client to confirm the readings, but it looks much more accurate now.

 

 

 Regards,
Armand 

[Charles_Murison]

Hello @ArmandV ,

ION7650 meters did support 0-20mA. The way the meter got equivalent output and scaling as 4-20 mA is with setup registers Zero scale and Full scale. 
Refer to ION reference version 14 (12/2023) page 41, for more information.

Glad to hear you got the ION9000 working.

Regards,

Charles

[ArmandV]

Hi @Charles_Murison ,

That is good to know.

Thanks again for the assistance!

Regards,
Armand