ABB DPU 1500R Instruction Book page 163

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Application Note
IRIG B Implementation in the DPU/TPU/GPU 2000/R and DPU1500R Units
IRIG B is a time code, which allows devices across the world to synchronize with a common time source to a resolution
of one millisecond. IRIG B allows each device to synchronize with the frame received by an IRIG B receiver. ABB's
DPU/TPU/GPU 2000/R and DPU1500R relays (herein referred to as an IED) offer IRIG B time synchronization
capabilities.
Figure 1 illustrates a typical IRIG B installation. An IRIG B time receiver accepts the RF signal and transforms it into
a one-second time synch frame. IEDs in the substation use the one-second time synch frame to govern their internal
clocks and event recorders.
IRIB B receivers/converters can format the IRIG B synchronization frames as a TTL-level pulse width, Manchester
Encoded or Modulated Carrier Frequency signal. TTL-level signals are pulse DC with a voltage range of 0 to 5V.
Modulated Carrier Frequency signals are pulse coded AM signals with modulation (tone bursts).
IRIG B is a general designation for time synchronization. There are many subsets to the IRIG B format. These were
developed to provide functionality primarily for military applications dealing with missile and spacecraft tracking, telemetry
systems, and data handling systems. IRIG B was embraced by the utility industry to answer a need to provide a
sequence of events capability between a group of substations. Care must be exercised to match the device demodulating
the signal from the satellite (downlink converter) with the IED's requiring specific IRIG B code formats.
DPU/TPU/GPU products support Pulse Width Code (X= 0), whereas, REL 3XX products having an IRIG B Poni Card
support Pulse Width Code and Sine Wave Amplitude Modulated, and REL5XX products support Sine Wave Amplitude
Modulated IRIG. If the IRIG signal supplied to the device is one in which the attached device cannot decode, the IED
shall not synchronize with the signal and IED will not calculate time correctly.
The IRIG B time code has a one-second time frame. Every frame contains 30 bits of Binary Coded Decimal time
information representing seconds, minutes, hours, days and a second 17 bit straight binary time-of-day. The frame
Applications Notes
A. Satellite Synch
Signal Received.
Figure 1. Typical IRIG B Architecture
ABB Distribution Protection Unit 1500R/2000R
B. Dish Sends received signal
to the downlink/receiver.
In the Substation
True Time
C. Demodulated signal transferred
to IEDs.
E C
website:www.abb.com/papd
E C
E C
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