Multi-Tech Systems 7500 - Manual (Page 350)

Clock Module Settings ION 7500 / ION 7600 User’s Guide
Page 350 Time Synchronization & Timekeeping Technical Note
Time Zone Adjustment:
The TZ Offset register specifies the time zone applicable to the area in which the
meter resides. It is obtained by adding or subtracting the appropriate number of
hours and minutes (hh:mm) from UTC time.
Daylight Savings Time Adjustment:
The DST Offset register holds the Daylight Savings Time offset applicable to the
meter’s location. The DST Offset is the amount of time in hours and minutes
(hh:mm) that the clock is adjusted when Daylight Savings Time begins.
N OTE
The setup registers, DST Offset and TZ Offset have no affect on the information recorded by a meter’s
data and event recorders. These recorders always use UTC as their timestamped reference.
Communications Port Used for Synchronization:
The Time Sync Source setup register specifies which communications port receives
time synchronization signals. Only signals received on the selected port are used
for time synchronization; all other time synchronization signals are ignored.
Signals can be received on the following ports:
N OTE
GPS Time Synchronization cannot be used with the Ethernet port, since time synchronization accuracy
cannot be guaranteed--there is no way to determine when a packet will arrive over the Ethernet.
Time synchronization can be achieved using ION and DNP 3.0 protocols. GPS time
synchronization uses special protocols defined for the type of GPS receiver you are
using. The following table summarizes the time synchronization sources:
1 Note that ION time synchronization only uses the UTC setting; the LOCAL setting cannot be used.
COM1 RS-232/RS-485 port COM3 optical port
COM2 RS-485 port or optional internal
modem 10Base-T Ethernet port
Source of Synchronization used
for the Time Sync Source Register Protocol Register in the
Communications Module Time Sync Type Register in
the Clock Module Clock Source Register in
the Clock Module
ION ION UTC1 LINEFREQ , INTERNAL
DNP DNP UTC / LOCAL LINEFREQ , INTERNAL
Arbiter 1092
GPS : ARBITER
GPS : ARBITER - VORNE
UTC / LOCAL COMM
True Time XL-DC GPS : TRUETIME / DATUM UTC / LOCAL COMM
Datum Exac Time GPS : TRUETIME / DATUM UTC / LOCAL COMM
Clark GPS-200-ASCII GPS : TRUETIME / DATUM UTC / LOCAL COMM