Issue
Old ION Setup version sometimes cannot communicate with meters using RS485/RS232 converter. Even though the ION Enterprise can communicate with the same physical connection.

Product Line
ION Setup

Environment
Power Monitoring Expert (PME)
ION Setup
Modbus mastering

Cause
Older versions of ION Setup uses a "processor" oscillation count to compute high accuracy millisecond timing. Now with dual and quad core processors, it can return different values depending on which processor is active when ION:S queries the value. Thus, instead of waiting 'X' ms to transmit... it does it immediately, causing issues.

The latest version of ION:S uses multi-media timers (similar to the one used in playing MOV files and such) and which have their own issues when under heavy loading (i.e. when playing MOVs, you sometime get jerky effects due to Windows being busy) but there are no other solutions that are acceptable and can be easily coded.

Resolution
Update ION Setup to the latest version.