54
Timing, IRIG-B and Pulses
Figure 7.2: IRIG-B Waveforms
7.3.3
IRIG-B IEEE 1344 Extension
As mentioned above, the IEEE 1344 enables extra bits of the Control Function (CF) portion of the
IRIG-B time code. Within this portion of the time code, bits are designated for additional features,
including:
•
Calendar Year (old method, now called
BCD
Y EAR
)
•
Leap seconds, and leap seconds pending
•
Daylight saving time (DST), and DST pending
•
Local time offset
•
Time quality
•
Parity
•
Position identifiers
To be able to use these extra bits of information, protective relays, RTU’s and other equipment
receiving the time code must be able to decode them. Consult your equipment manual to determine
if the IEEE 1344 feature should be turned ON in the clock. To view details of the IEEE Std 1344-
1995, please check with the IEEE.
NOTE
: To download a copy of of the IRIG-B 2004 specification, please use the link to the Arbiter
web site.
http://arbiter.com/resources/documentation.php and select Timing and Frequency, then select Ap-
plication Notes/Option Information.
7.3.4
1 Pulse-per-Second (1 PPS)
A one pulse-per-second timing output signal is very simple in concept. It is a digital bit transmitted
every second with a pulse width of 10 milliseconds. Probably the most critical part of this signal is
that the rising edge is “on time” as compared with the signal from the Global Positioning System
(GPS). When configured from any of the TTL/CMOS (5-volt) drivers, it has the same drive power
as the IRIG-B and the Programmable Pulse. See Figure 7.2 for a comparison between unmodulated
IRIG-B and 1 PPS.
Summary of Contents for 1084A
Page 4: ...iv ...
Page 6: ...vi ...
Page 18: ...xviii LIST OF FIGURES ...
Page 24: ...4 Unpacking the Clock ...
Page 36: ...16 Connecting Inlet Power Input and Output Signals ...
Page 44: ...24 GPS Antenna and Cable Information ...
Page 114: ...94 Startup and Basic Operation ...
Page 123: ...B 4 Physical Dimensions 103 Figure B 1 Suggested Mounting of the AS0094500 Surge Arrester ...
Page 124: ...104 Using Surge Arresters ...
Page 134: ...114 Options List C 6 2 Option 06 Firmware Setup Figure C 3 Option 06 Firmware Setup ...
Page 142: ...122 Options List Figure C 5 Option 06 Output Jumper Settings ...
Page 158: ...138 Options List Figure C 13 Option 17 Board Layout and Jumper Locations ...
Page 163: ...C 13 Option 20A Four Fiber Optic Outputs 143 Figure C 14 Option 20A Jumper Locations ...
Page 170: ...150 Options List Figure C 16 Option 23 Internal Jumper Setup ...
Page 172: ...152 Options List Figure C 17 Option 27 Jumper Locations ...
Page 190: ...170 Options List Figure C 20 Option 29 Connector Signal Locations ...
Page 246: ...226 Options List ...