Issue
Instructions on how to set the time on an ION73xx meter using Modbus.
Product Line
ION7300 Series (ION7300, ION7330, ION7350)
Environment
ION73xx meters – Time configuration using Modbus protocol
Resolution
Using the Modbus protocol, it is possible to set the time on ION7300 series meters. This process is not a time synchronization (since there is no external source continuously sending a signal), but you can use Modbus software to automate the process by retrieving time from a source and passing it to the meter.
To set the Meter time via Modbus communications do the following:
1. Set the ION Clock Module Time Sync Source Register to the Modbus
communications port.
2. Write the UNIX time in seconds as an unsigned 32-bit value to Modbus
Registers 41926 (high order) and 41927 (low order).
Steps to Set Time via Modbus
- Convert the desired time to UNIX time (seconds since 01/01/1970 UTC).
- Split the UNIX time into two 16-bit values:
- Lower order 16 bits → Register 41927
- Higher order 16 bits → Register 41926
Example
- UTC Time: 07/01/2009 02:00:01 AM
- UNIX Time: 1246413600 (decimal)
- Binary: 0100 1010 0100 1010 1100 0011 0010 0000
- Lower order bits: 1100 0011 0010 0000 → 49952 (decimal)
- Higher order bits: 0100 1010 0100 1010 → 19018 (decimal)
Write:
- 49952 to register 41927
- 19018 to register 41926
The meter will now display the correct time and continue ticking based on its internal clock.
