Trimble Outdoors 58052-00 Benutzerhandbuch

Copernicus GPS Receiver     5 7

OPERATING MODES     4

When the receiver enters Standby Mode through the software protocol commands, 
the first condition for exiting Standby Mode is using serial port A activity or serial 
port B activity. The condition is identical for both ports A and B. 

To ensure the receiver detects and responds to serial port activity, issue a NULL 
character on the selected serial port to bring the unit out of Standby Mode. In Standby 
Mode, the receiver samples for serial port activity at a rate of 32.768 kHz. A NULL 
character will bring the selected RX line low for 9 bits so even at the highest baud rate 
of 115200, a NULL character should be detectable at the sample rate.

There are two exceptions where serial activity may not trigger the unit to exit Standby 
Mode:

•

During the 3 seconds following the command to enter Standby Mode.

The Copernicus GPS receiver may not detect serial port activity during the 3 
seconds immediately after receiving a software command to enter Standby 
Mode. During that 3 seconds, the unit is processing the shut-down command 
and will ignore serial port activity. Therefore the minimum time between 
issuing the shut-down command and the use of serial port activity to return the 
unit to Run Mode is 3 seconds. Standby time cannot be less than 3 seconds. 

•

During the 10 msec RTC service time.

During the 10 msec RTC service time, there exists a 91.6 

μsec window where 

the receiver cannot detect serial port activity. Using a series of three NULL 
characters in a row should ensure that the unit responds. (See 

 for an explanation of the RTC service time.)

The second condition that will trigger the receiver to exit Standby Mode is the elapse 
of a pre-defined time. When the receiver is placed into the Standby Mode using 
protocol commands, the receiver can be made to exit the Standby Mode after a 
defined elapsed time using TSIP command Packet 0xC0 or NMEA packet RT. In this 
case, the user specifies the number of seconds the receiver should stay in Standby 
Mode. After this time has elapsed, the unit will perform a reset and start operating 
normally.