Technical data

Installation & Operation Manual GM-TTT
Page 53
3.12 ZONE
The local time zone of the internal clock is defined by the following parameters: Time offset
with respect to the reference time during normal time or Daylight Saving Time, and moments
of time of the switchover from normal time to DST and vice versa.
OFFS 1
Time zone offset during normal time.
OFFS 2
Time zone offset during Daylight Saving Time (DST).
DST on
Program the beginning of the DST.
DST off
Program the end of the DST.
(DST period)
Indicate beginning and end of DST of the current year.
ZONE
RESET A-F
Reset the parameters of the time zones for the timer A - F.
By using the parameters “DST on“ and “DST off“, the automatic time zone system of the
internal clock calculates the switchover times. The calculation is carried out by the GM-TTT
whenever the year or the parameters are changing. The result can be checked in the “DST
period” menu line. Hour = 00 is not possible. If there is a switchover at 00 o'clock (which
never happened until now), hour = 24 of the previous day should be selected. But principally
the GM-TTT will not reset the current date, even not during a time switchover. OFFSET 1,
OFFSET 2 and the difference must make a sense. Example for an entry which does not make
any sense: OFFSET 1 = +02 and OFFSET 2 = -02, in this case the difference would be = -04
during switchover to Daylight Saving Time! If the switchover occurs at 03 o'clock, the GM-TTT
will switch to 23 o’clock of the same day!
Examples for input (reference time) and output (time zone) with different operating modes:
Refer-
ence
input
Time zone output and
automatic switchover
‘Mode’ para-
meter at menu
REFER-MODE1
Offset 1
Offset 2
without
DST
without DST,
no automatic switchover
0 Offset 1
without
DST
with DST, with automatic
switchover
u, U internal clock at normal time: Offset
1
internal clock at DST: Offset 2
with
DST
without DST, without automatic
switchover
i, I Reference at normal time: Offset 1,
Reference at DST: Offset 2.
The switchover parameters must be
identical with the switchover times of
the reference.
with
DST
with DST, without automatic
switchover
0, c, C Offset 1
with
DST
with DST, with automatic
switchover
o, A Offset 1 (*1
*1*1
*1)
(*1) Only offset 1 is added/subtracted, if the internal clock is set by the reference time. How-
ever, the correct entry of offset 2 is relevant in case of a DST switchover, because there is
a time jump equal to the difference of offset 1 - offset 2. Example: Time zone output =
reference = CET (Central European Time)/CEST: set offset 1 = 0 and offset 2 = 1!