Irig Timer; Table 5.2-Hardware Versus Software Designation Of Discrete I/O - BALLARD L 1553-5 Series User Manual

Table 5.2 below shows the correlation between dionum and its hardware
reference designator. The last column shows how these discretes are used as
trigger inputs and sync outputs in the BTIDriver API functions.
Table 5.2—Hardware Versus Software Designation of Discrete I/O

5.4 IRIG Timer

An IRIG time signal contains a human-readable binary coded decimal (BCD)
time value in days, hours, minutes, seconds, etc. and can be used to synchronize
many devices. This allows timing data from all compatible devices to be easily
correlated.
Note: An IRIG signal is not available on Lx1553-5/1xT models.
The Lx1553-5 IRIG circuit can be configured as either a master or a slave. The
IRIG timer pin is driven by the bidirectional buffer only when the IRIG timer is
configured as a master. When the IRIG timer is configured as a slave, it will
expect the IRIG signal to come from an external device.
The Lx1553-5 internally uses a binary system timer that is free running and
keeps time until either set by software or synchronized to an IRIG signal when
configured as a slave. This system timer is also the source for the IRIG interface
when configured as a master. The system timer has a resolution down to one
microsecond.
Note: The clocks in the master and slave can vary in accuracy. As a
result, there can be a slight underflow or overflow in the least
significant digits of the system timer each time the IRIG timer is
resynchronized.
IRIG data can be encoded using Pulse Code Modulation (PCM), Modified
Manchester Modulation, or Amplitude Modulation (AM). The Lx1553-5
supports PCM master, PCM slave, or AM slave modulation modes.
There are a number of formats for IRIG timing. The Lx1553-5 uses the IRIG
formats indicated in Table 5.3 and Table 5.4. The characteristics of the external
electrical interface to the IRIG pins are as shown in Table 5.5.
Lx1553-5 User's Manual
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
Hardware API API
Reference dionum usage
DIO0 1 Trigger A
DIO1 2 Trigger B
DIO2 3 Trigger C
DIO3 4 -
DIO4 5 -
DIO5 6 -
DIO6 7 -
DIO7 8 -
DIO8 9 Sync A
DIO9 10 Sync B
DIO10 11 Sync C
DIO11 12 -
DIO12 13 -
DIO13 14 -
DIO14 15 -
DIO15 16 -
LX1553-5 FEATURES
5-5