44 Programming T801-4 Installation and Operation Manual© Tait Electronics Limited September 2007If the system decides that the 1PPS signal is invalid, the control process willhold the DAC at the last known good setting. When the 1PPS status returnsto a valid state, the control process will start again from where it stopped.This event can be seen in the above example as a gap in the time sequence(arrowed).3.5 Viewing the GPS StatusThe GPS screen provides information about the status of thecommunications between the Satsync 7 module and the GPS satellitesystem. To open the GPS screen, click GPS on the monitoring screen.The GGA, GSA, GSV and RMC (or TPS) LEDs flash alternately green andyellow when the GPS receiver is communicating with the Satsync 7module. The screen at left is displayed when the Satsync 7 module isconnected to the Trimble internal GPS receiver. The screen at right isdisplayed when the Satsync 7 module is connected to the Dalman externalGPS receiver.Note Some fields will not display any data until a tracking fix has beenestablished. The GSA string may or may not be displayed,depending on the type of GPS receiver used.The information available on this screen is explained in the followingparagraphs.Time, Date,Latitude, Longitude,AltitudeThese parameters are displayed for information purposes only. They haveno effect on the operation of the Satsync 7 module.Trimble internal GPS receiver Dalman external GPS receiver