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Issue with Modbus Profile – Data Not Showing on Mapped Group Address
#1
I am currently integrating a LogicMachine controller with a Labtech Ultrasonic Water Meter using the attached JSON Modbus profile. The profile is configured to read Instant Flow and Total Flow values as 4‑byte floating point (float32) objects.
I have successfully tested communication through the Modbus “Read Test” tool in LogicMachine, and the correct data is being received from the meter. However, the mapped group addresses linked to this Modbus profile are not displaying the values — they remain at 0.000.

Could you please advise what might be causing this issue? Specifically, I would like guidance on whether this could be related to:
  • Datatype mismatch between the Modbus profile and LogicMachine objects
  • Word/byte order configuration (read_swap setting)
  • Register addressing for float32 values (two registers per value)
  • Scaling or multiplier settings
Any insights or recommended adjustments would be greatly appreciated.
Thank you in advance for your support

Attached Files Thumbnail(s)
   
.json   Water Meter.json (Size: 781 bytes / Downloads: 1)
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#2
Instant Flow address should 0, not 1. Total Flow address should 2, not 3.

Post a screenshot of Read test values that work for you.
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#3
(10.06.2026, 06:45)admin Wrote: Instant Flow address should 0, not 1. Total Flow address should 2, not 3.

Post a screenshot of Read test values that work for you.

Sure 

I have Attached

Attached Files Thumbnail(s)
   
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#4
Which Address, Data type and Read swap settings have you used?
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#5
(10.06.2026, 06:54)admin Wrote: Which Address, Data type and Read swap settings have you used?



Device address was 95

Attached Files Thumbnail(s)
   
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#6
Set Address to 0, Data type to float32, Read swap to Word (CDAB). Post what result you get when reading the value.
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#7
(10.06.2026, 07:00)admin Wrote: Set Address to 0, Data type to float32, Read swap to Word (CDAB). Post what result you get when reading the value.

Attached Files Thumbnail(s)
   
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#8
Do you have Modbus register map documentation for your device?
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#9
(10.06.2026, 07:05)admin Wrote: Do you have Modbus register map documentation for your device?

Sir,

I have only these two Document.

Attached Files Thumbnail(s)
   
.pdf   ULTRAFLOW 500L with RS485 MODBUS.pdf (Size: 3.98 MB / Downloads: 2)
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#10
The correct data type is int32. Try both Address 0 and 1 and Read swap Word/None until you get a value that matches the meter reading.
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#11
(10.06.2026, 07:21)admin Wrote: The correct data type is int32. Try both Address 0 and 1 and Read swap Word/None until you get a value that matches the meter reading.

Done

Its Showing Now 

Thanks A Lot
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