Read Modbus holding register value as floating point

[hussey]

Hi,

working with a system Crowcon make Gasmonitor having communication protocol as RS232 but having multiple instrument, I used Modcon module (RS232-Modbus RTU converter used to read 3 devices). Reading value of registers and as per requirement using typecast function also. However, not able to interpret data format.

Also tried with modscan software which is also gives some number which is difficult to understand, image attached.

On Hardware crowcon make Gasmonitor+ values in 20ppm while in labview it shows -3.7782E+8.

How to co relate this, can anyone help to understand this logic?? or  any other suggestions.

[pincpanter · Accepted solution]

The resulting floating point value has 4 bytes, therefore you need to type cast to a SGL, not a DBL.

[wiebe@CARYA]

Search the community for "modbus float" - NI Community

[RTSLVU]

Try this: