converting modbus 32 bit floating data in to integers

[vinguptain]

i am communicating 1766-l32bwb with conzerv make energy meter em 6436. I have communicated it on Modbus rtu. but i am not able to decode the data. The energy meter is sending 32 bit floating data to plc. i want to decode the data.

 

[Ken Roach]

I can infer from your statements that you want some suggestions about how to convert the two 16-bit Modbus integers into a Floating Point value.

The general approach is to use the Copy Word (CPW) instruction to copy two Integer data table elements into one Floating Point data table element.

Because it sounds like you are using MSG instructions and using the MicroLogix 1400 as Modbus RTU Master, you can trigger the CPW instruction using the /DN bit from the MSG instruction.

The byte order and word order from third party Modbus devices is frequently different from the byte order necessary for the Floating Point data type, so often "swapping" the bytes or words of the data before copying it into a Floating Point register is necessary.

I frequently do this by trial-and-error. If you post the values you are getting in Integer format and what value they are supposed to represent in Floating Point, then Forum members may be able to help.

 

[nguyenhphuc]

i am communicating 1766-l32bwb with conzerv make energy meter em 6400 thru 1763 NC-01 cable. I have communicated it on Modbus rtu. but em 6400 only have 2 wire A+, B-. 1763 NC-01 need 3 wire. So, how can i connect?
Thanks.