Novatel OM-20000053 Rev 2 DGPSTIMEOUT

C Commands Summary
92 MiLLennium GPSCard SW Version 4.503/4.52 Command Descriptions Manual Rev 2
DGPSTIMEOUT
This command has a two-fold function:
(1) to set the maximum age of differential data that will be accepted when operating as a remote station. Dif-
ferential data received that is older than the specified time will be ignored. When entering DGPS delay,
you can ignore the ephemeris delay field.
(2) to set the ephemeris delay when operating as a reference station. The ephemeris delay sets a time value
by which the reference station will continue to use the old ephemeris data. A delay of 120 to 300 seconds
will typically ensure that the remote stations have collected updated ephemeris. After the delay period is
passed, the reference station will begin using new ephemeris data. To enter an ephemeris delay value, you
must first enter a numeric placeholder in the DGPS delay field (e.g., 2). When operating as a reference
station, DGPS delay will be ignored.
Syntax:
Example 1 (remote):
dgpstimeout 15
Example 2 (reference):
dgpstimeout 2,300
NOTE 1: The RTCA Standard for SCAT-I stipulates that the maximum age of differential correction messages
cannot be greater than 22 seconds. Therefore, for RTCA logs, the recommended DGPS delay setting is
22.
NOTE 2: The RTCA Standard also stipulates that a reference station shall wait five minutes after receiving a new
ephemeris before transmitting differential corrections. This time interval ensures that the remote
stations will have received the new ephemeris, and will compute differential positioning based upon the
same ephemeris. Therefore, for RTCA logs, the recommended ephemeris delay is 300 seconds.
DGPSTIMEOUT dgps delay ephem delay
Command Option Description Default
DGPSTIMEOUT Command
dgps delay min. 2
max. 1000 Maximum age in seconds 60
ephem delay min. 0
max. 600 Minimum time delay in seconds 120