Problem Reading Swapped Byte Float Data

Because you mentioned you entered FloatMode=1 in MODBUS parameter section, I assume this is the serial Modbus protocol, using MODBUS driver in Citect. If you are using ethernet modbus with driver MODNET, you should place the parameters in the MODNET section. Can you explain which protocol you use in your I/O device configuration?

Have you tried all possible FloatMode modes (0 to 3) yet?

Do you have success with single register values, like integers? Or do you experience an address shift (1 address higher or lower than your device documentation)?

Are you sure it is a floating point number? For double-integers (type LONG in Citect) you can adjust another parameter called LongDataType.

OK, just found a product sheet of the meter that answers some of my questions.

It is a modbus RTU device, so you do not need the MODNET driver.

And there are only float registers that you can read, so I would experiment with:

a) the protocol variant: MODBUS or MODBUS1. MODBUS protocol in Citect means first available modbus address is 1, MODBUS1 means first address is 0. If you have success in reading values when your variable address is 1 lower or higher than the documentation, please switch to the other driver variant.

b) the FloatMode parameter: try modes 0 to 3 for each protocol variant.

OK, just found a product sheet of the meter that answers some of my questions.

It is a modbus RTU device, so you do not need the MODNET driver.

And there are only float registers that you can read, so I would experiment with:

a) the protocol variant: MODBUS or MODBUS1. MODBUS protocol in Citect means first available modbus address is 1, MODBUS1 means first address is 0. If you have success in reading values when your variable address is 1 lower or higher than the documentation, please switch to the other driver variant.

b) the FloatMode parameter: try modes 0 to 3 for each protocol variant.