TW5310 User Manual
12
©2011 Tallysman Wireless, Inc.
Confidential
4.5
1PPS Qualification
A 1PPS qualification signal is provided to indicates when the 1PPS output is valid,
qualification is based on a GPS fix with DOP <15.
See section 3 for wiring details
Figure 8 shows the internal 1PPS qualification status of the TW5310. Once the 1PPS
status is detected as good, a 1PPS Start Delay is inserted before the 1PPS qualification
signal is output to ensure that the TW5310 has time to average out the satellite clocks
and provide a stable 1PPS output.
On loss of 1PPS qualification status the 1PPS qualification output is maintained for the
1PPS Stop delay. During the 1PPS Stop delay time the TW5310 flywheels to maintain
timing.
0V
3.3V
1PPS Qualification output
1 PPS Qualification status
1PPS
Qual Start delay
1PPS
Qual stop delay
Figure 8
The signal levels 0V to 3.3V.
The default 1PPS Qual Start and Stop delays are set to 10 seconds.
4.6
Baud Rate
The TW5310 baud rate is configurable from 4800 bps to 115kbps
The default baud rate is 4800 baud
Note1: After changing the baud rate ensure that the baud rate of the connected
application matches that set otherwise you will be unable to communicate with the
TW5310.
