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.

Released for: Schneider Electric Thailand