5 Hardware
PCS-9785 Satellite-Synchronized Clock
5-6
Date: 2014-10-15
Do
NOT
look into an optical port/connector.
A direct sight to laser light may cause temporary or permanent blindness.
NOTICE!
Each IRIG-B input channel supports optic ST connector and RS-485 serial port.
However, these two modes should be used exclusively.
The correct serial port wiring is shown in the following figure. Generally, a foiled cable with at least
two pairs of twisted pairs shall be applied. One pair of the twisted pairs are respectively used to
connect the "+" and "-" terminals. The other pair of twisted pairs is used to connect the signal
reference "SGND" of the communication interface. If there is a free terminal or a grounding
terminal "FGND" for all the communication ports, it is suggested to connect the foiled layer of the
cable when connecting multiple devices in series. The foiled layer connection of the cable shall be
grounded at only one end.
01
02
03
SYN+
SYN-
SGND
FGND
04
Twisted
pair wire
To the screen of other cable with
single point earthing
IR
IG
-B
S
ign
al
01
02
03
L
N
FGND 04
To the screen of other cable with single point
earthing or the mains power line (ground)
Ti
m
e Fr
eq.
M
ea
su
rem
en
t
Mains power line (live)
Mains power line (neutral)
Figure 5.5-2 Wiring of synchronization port (CLK module NR1145)
For NR1145J, the reception mode of IRIG-B time synchronization signal could be selected by
configuring the following 2 jumpers.
Table 5.5-2 Jumpers for IRIG-B signal reception mode
Jumper
RS-485
TTL
J6 & J7 for serial port 1
J8 & J9 for serial port 2
Remark
Pin 1-2 ON
Pin 2-3 OFF
Pin 1-2 OFF
Pin 2-3 ON
5.5.2 NR1141 for Clock Extension
The CLK module NR1145 receives and processes satellite signal and external IRIG-B code. It
converts them into PPS/PPM/PPH, IRIG-B code and timing message and transmits them to the
MON module and COM modules via the internal bus.
08020
08020
08020
08020
08020
08020
08020
08020
08020