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Issue
The ION 75xx RTU reads -1 for all external numeric registers and will not save any changes after a register write.
Product Line
ION7550 RTU
ION7500 RTU
Environment
ION Framework
Cause
The ION 75xx RTU units do not come with predefined framework on the meters. If a module does not exist on the framework, Modbus requests will return -1.
Resolution
Use ION Setup or ION Designer to create external numeric modules and unlock the registers. Once the module has been created the register will read 0 instead of -1.
