Modbus TCP - 4 Consecutive Registers with Double Conversion

Ignition
1

Hi, I am attempting to read 4 consecutive registers via Modbus.

I currently have the communication working properly for 2 consecutive registers, using the HRF designator.
Example: [DEVICE_NAME]1.HRF4667

But when I attempt to access a value using the HRD designator, I am receiving a value of 0 (I am expecting a non-zero value).
Example: [DEVICE_NAME]1.HRD2021)

Is there anything I may be missing? Or is the only possibility I am pointing to the wrong address?

Ignition Version 8.1
Modbus TCP Driver

2

It is also possible that the device doesn't use the word order for quad-word values that Ignition is expecting.

Try reading the four registers as unsigned integers, and combine them in various orders using an expression, and passing that 64-bit value to Double.longBitsToDouble().

1 Like