ION9000 & GE G100 RTU Integration

[vthakar]

Hi Team,

I have question. I have 4 ION 9000 meters. I have configured as per Modbus map available table on Schnider Electric default registery address and values I will poll as a FLOAT 32. My GE G100 RTU will poll the information as float 32. My SCADA only accepts UINT 16. In this direction, what should I be doing in order to measure the correct value on SCADA?

ION 9000 - Modbus Mapping - Using the default registery added.

GE G100 - I have scaled and mapped with DNP3

PRISM SCADA DNP3 - Receives only UINT 16 only.

Where should I make the conversion at Meter or GE G100 RTU ? what is schnider electric recommendation ?

[Charles_Murison · Accepted solution]

Hello  ,

Is there a reason you are not collecting data from the meter's DNP directly? 

There is no official best place to do the conversion. Each place comes down to how much work to do the conversion and how much you trust the device to do the conversion.

ION9000 meters you cannot change the default mapping however you can use Modbus Slave modules to create custom Modbus mapping including the data format. This means you can do the conversion on the meter and have the modbus be UINT16. To get any resolution you would need to do some scaling.

I do not know the GE G100 so I cannot give an hints on the work needed to do the conversion.

Note in both cases you may loose some resolution depending on the measurement being read.
UINT16 has only whole numbers, to get decima places you multiply value first, then divide at the end. Example: to send 120.1, multiple by 10 = 1201, modbus transfers 1201, system scales by 10 to get 120.1.
to send 120.13, multiple by 100 = 12013, modbus transfers 12013, system scales by 100 to get 120.13
to send 120.1345 would exceed the limits of UINT16.

Regards,

Charles