GPS Timing Board with ISA Interface
- GPS-synchronized timecode generator
- GPS, IRIG-A, IRIG-B, NASA36 timecode reader
- IRIG-B timecode generator
- Time-Tag input
- Freewheel capability
- Programmable periodic output (pulse/squarewave) and interrupt
- Programmable start/stop time output and interrupt
Product Overview
The TSAT-PC is a complete system package including the GPS Receiver/Antenna (housed in a common enclosure), and a circuit card assembly for the bus. The board synchronizes its on-board clock to Coordinated Universal Time (UTC). Other features include a time-tag TTL input, a programmable “heartbeat” pulse or squarewave output (with interrupt capability), and a programmable “match” start/stop time output (with interrupt capability).
The board continues to increment time (“freewheel”) in the unlikely event that reception of the satellite signals is lost. When the signals are re-established, the board resumes synchronization automatically.
The GPS satellites provide Coordinate Universal Time (UTC) accurate to one microsecond. A programmable time offset allows for compensation for cable delays. They also provide position (longitude, latitude, and elevation).
ISA Interface
The TSAT-PC occupies 16 consecutive addresses in I/O (not memory) space. Jumpers allow for selection of base address; and a separate jumper can be used to select the interrupt level. All board functions can be used without interrupts, if desired.
All functions can be accessed using 8-bit transfers. In addition, the time can be read with four 16-bit transfers. The board uses binary-coded decimal (BCD) format for setting and reading the time.