Using the modbus protocol, it is possible to set the time on an ION7300, ION7330, and ION7350 meters. This is not a time synchronization as there is no source sending a signal out to the device, however it is possible to use a modbus software to automate this process and get time from a source and pass this time to the meter over modbus.

In order to time synchronize an ION73xx meter using modbus, it must be done by converting unix time into two 16 bit values. These values are then passed to the 41926 and 41927 registers.

The time being passed to the meter must first be converted to UNIX time. The UNIX time is then split into a higher and lower order 16 bit values. For example:

UTC time: 07/01/2009 2:00:01 AM

UNIX time: 1246413600 (decimal)

UNIX time: 0100 1010 0100 1010 1100 0011 0010 0000(binary)

Lower order bit: 1100 0011 0010 0000 (binary)

Lower order bit: 49952 (decimal)

Higher order bit: 0100 1010 0100 1010(binary)

Higher order bit: 19018(decimal)

At this point the user can pass 49952 into register 41926 and 19018 into register 41927. The meter will now display 07/01/2009 2:00:01 AM, and will continue to tick away based on the clock source.

Date Created: November 27, 2009
Last Revised: December 23, 2009
Public
Original Author: TO
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