Issue
Customers have migrated Quantum CPUs to M580 CPU and accuracy of analog inputs is a key point for the most part of the process. So, the comparison between the two modules will show you the differences.

Product Line
Modicon M580 CPUs, Modicon M340 CPUs, Modicon Quantum CPUs

Environment
BMXART0814, 140ATI03000

Resolution
About thermocouple J, the measurement range is from -210°C to 760°C.
If the module is under 0°C to 60°C, then:

• 140ATI03000 -> +/- 2°C + 0.1% of reading thermocouple J

If the customer set resolution as 1°C (default):
The maximum error is 2°C +0.1% of reading, which is 2°C +0.76°C that means 3°C.

If customer set resolution as 0.1°C:
The maximum error is 2°C +0.1% of reading, which is 2°C +0.76°C that means 2.8°C.

If the thermocouple is under -100°C then: maximum error is 3°C +1.5°C =5°C with resolution 1°C (default), and 2.8°C +1.5°C =4.5°C with resolution 0.1°C
So conclusion: normal case, maximum error is 2.8°C or 3°C. Worst case, maximum error  is 5°C or 4.5°C

• BMXART -> +/- 2.8°C thermocouple J 25°C, +/- 4.5°C thermocouple J 0...60°C, +/- 5.5°C thermocouple J -25...70°C

Conclusion:
When module is under 25°C: BMXART0814 has the same accuracy with 140ATI03000, even better since resolution is better than 140ATI03000.
When module is under 0°C to 60°C: BMXART0814 has the same accuracy with 140ATI03000 (worst case), even better since resolution is better than 140ATI03000.

Released for: Schneider Electric Philippines