3 Operation Theory
PCS-9785 Satellite-Synchronized Clock
3-1
Date: 2019-07-05
3.1 Overview
This device adopts modular design for its hardware and software. For hardware, MON module,
CLK module and COM module are integrated. For software, reception function, time service
function and output function are integrated.
The PCS-9785 receives standardized time signals, such as BDS, GPS, IRIG-B, via its built-in
receiver. After a decode, it converts the source time into IRIG-B, PPS, PPM, PPH signals or timing
message, and sends them via various output interfaces.
C
LK
m
od
ul
e
Inner Bus
PPS
Signals
Timing
Messages
PPM
Signals
IRIG-B
Signals
C
O
M
m
odu
le
C
O
M
m
odu
le
C
O
M
m
odu
le
C
O
M
m
odu
le
Timing signals
BDS, GPS, IRIG-B
SNTP/NTP
PTP
MMS
M
O
N
m
odu
le
Time
service
PPH
Signals
C
O
M
m
odu
le
Reception
Output
...
Figure 3.1-1 Operating sketch
3.1.1 Reception Function
The reception function takes the received timing signal as its external time reference. Its main
components include antenna, feeder line, low-noise amplifier, surge protector and BDS/GPS
receiver.
3.1.2 Time Service Function
The time service function will decode and convert the time reference. Depends on the "Multiple
sources judgment" and "Optimization selection", it selects the optimizing external time reference,
makes it to be the clock synchronization source, set the source in tracking and fixing status and
compensates the transmission delay.
If all external time references are lost, the internal clock will enter the "Punctuality mode" to
maintain its accuracy. After the recovery of any external time reference, the internal clock will quit
the "Punctuality mode" and takes the "Tracking and fixing mode" again. In this period, there is no
influence to the output function.
08020
08020
08020
08020
08020
08020
08020
08020
08020