Bus-Level Timing Board

The PC104-SG provides precision timing to a host computer through the PC/104 bus. The on-board microprocessor can automatically synchronise the clock to a range of signal inputs, e.g. 1PPS, IRIG and NASA time codes, GPS and HaveQuick.

  • Continual time error measurement between on-board clock and the reference input signals.
  • Error measurement adjustment for propagation delay.
  • Range of input and output options, including IRIG timecodes
  • Optional disciplined TXCO or OXCO.
  • 3 user-programmable pulse rates
  • Optional GPS receiver
  • Time-tagging of external events
  • Match Time feature, from which Internal or External processes may be automatically initiated or terminated
  • Variation – see PC/104-Plus below

Optional Disciplined Oscillator
Enhance performance by selecting optional disciplined TXCO or OXCO. By locking the oscillator to the synchronising time source, the oscillator is automatically calibrated, ensuring that a precise timebase is always available. During periods where there is no synchronising time source, the performance of the module reverts to the oscillator specification. When the input signal is available the oscillator will return to normal disciplining.

58 bits of BCD time data are available to the host computer using two zero latency time reads. The time message contains units of microseconds through units. A status word is available using an additional read.

Pulse Rates
The PC104-SG provides three user programmable pulse rates. Two pulse rates, Clock Low and Clock High, are available on the multi-pin connector. The third rate generator provides heartbeat timing to the host computer.

Optional GPS Receiver
The optional on-board GPS Receiver receives and decodes transmissions from GPS satellites, allowing the timing system to accurately synchronise to Universal Coordinated Time (UTC). Automatic leap year, leap second correction and accurate positional information are additional benefits provided by the GPS option.

N.B. Software packages are available as options. C language examples are supplied as standard.


This is an advanced version of the PC104 SG module that conforms to PC/104Plus 2.0, and has many of the standard features including IRIG A, IRIG B and NASA 36 Time Code inputs as well as an extensive library of extra options to customize to fit your need.


  • IRIG’s A and B and NASA 36 time code inputs
  • +3.3V or +5V signaling
  • 1PPS Sync input
  • External Event (Time Tag) input
  • Three programmable pulse rate outputs
  • Match Time output
  • Industrial Temperature Range option
  • Optional on-board GPS option
  • Optional HaveQuick input/output
  • Optional IRIG B time code output

Alternative Products

PCI SyncClock32