Modbus RTU serial 485 read a double float

Ewon Support Ewon Flexy
#1

I am new to the Flexy. I am a system integrator attempting to collect a flow meter totalizer register that is a double float via Modbus 485. I have established a connection and successfully collected integers and single floats. The totalizer is a large number that is only represented as a double float for accuracy. I am using a 201 with a serial card.

Read Int64 Modbus Registers
#2

@RichFranzo

The eWON will only be able to read a maximum of 32 bits.
Double floats are not natively supported in the eWON due to this (64 bits).

#3

Thanks for the response Joe.
Although the double float is a 64 bit number it resides in the meter as four words. The problem is I can’t collect four words with the Ewon, the “Data Type” selection limits me to an Integer (one word) or float (two words).
Currently I use a 32bit PLC to collect the four words and then manipulate it to a 32 bit float. In the PLC I can tell it to start at this address and collect four words. Is there any work around in the Ewon where I can tell it to collect four words? The only thing I use the PLC for is to collect and manipulate this data point.

Thanks,
Rich

#5

@RichFranzo

You could try reading these 4 Word registers separately and compute the 32 bit equivalent value in BASIC and store it in a Tag. However, you will lose precision when doing this.