# Combining Modbus Registers Indirectly

**URL:** <https://forum.inductiveautomation.com/t/combining-modbus-registers-indirectly/91105>\
**Category:** Ignition\
**Tags:** modbus\
**Created:** [May 29, 2024, 8:21pm UTC](https://forum.inductiveautomation.com/t/combining-modbus-registers-indirectly/91105 "2024-05-29T20:21:40Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\
**Post date:** [May 29, 2024, 8:51pm UTC](https://forum.inductiveautomation.com/t/combining-modbus-registers-indirectly/91105/2 "2024-05-29T20:51:16Z")

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What is the exact expression you were using? Do you have the high and low words brought in as OPC tags already, and you're now just creating a 3rd expression tag to combine them?

P.S. the float case is tricky and can't be done with the expression language alone: [64-Bit Double Little Endian Input Register - #25 by Kevin.Herron](https://forum.inductiveautomation.com/t/64-bit-double-little-endian-input-register/73987/25) (there's also a corresponding `Float.intBitsToFloat` in the Java standard library)

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