CHAPTER FOUR
4.49 AUTOMATIC DAYLIGHT SAVINGS TIME
This feature provides the capability of offsetting the time by one hour to compensate for daylight
savings time. It can be turned on and off using the front panel keyboard. It can also be
programmed to automatically turn on /off for up to ten years using the RS-232 I/O port. Each
time this feature is accessed from the I/O port, two commands need to be issued which consist
of:
A Primary Command
• The user inputs $O (HEX 24/HEX 4F).
A Secondary Command
One of five secondary commands can be issued (in conjunction with the primary command) to
perform the following functions:
4.49.1 DISABLE AUTO DAYLIGHT SAVINGS TIME FUNCTION
This command disables the daylight savings time feature.
• The user inputs D (HEX 44).
• The unit responds with OK followed by CR/LF (carriage return/line feed).
Example: $OD
4.49.2 ENABLE AUTO DAYLIGHT SAVINGS TIME FUNCTION
This command enables the daylight savings time feature.
• The user inputs E (HEX 45).
• The unit responds with OK followed by CR/LF.
Example: $OE
4.49.3 SET AUTO DAYLIGHT SAVINGS TIME DEFAULT INTERVAL
This command allows the following daylight savings time intervals to be loaded into memory.
If you want the unit to automatically increment/decrement, the following command must be
proceeded by the ENABLE command.
• The user inputs F (HEX 46).
4-26 ET6xxx ExacTime GPS TC & FG (Rev C) Symmetricom Inc