VME635091 SyncClock

VME Time & Frequency Processor

P/N 001000157


Brandywine Communications’ VME635091-SYNCCLOCK is a time and frequency processor module that provides precision time and frequency reference to the host computer and peripheral data acquisition systems. Time is acquired from time code signals, typically IRIG B. Time is displayed on the front panel (hours, minutes, seconds) via LED digits.

Central to the operation of the module is a disciplined 10 MHz oscillator and 100-nanosecond clock. Current time (days to 100 nanoseconds) can be accessed across the bus with zero latency, which allows for very high-speed time requests. The oscillator is rate matched (disciplined) to the input time source and drives the precision 10 MHz frequency output and time code generator circuitry. If the time source is lost, the module will continue to maintain time (flywheel).

Both time code generation and translation are supported. The generator supplies IRIG B time code output that is synchronized to the input time source. The translator decodes IRIG B time code inputs.

An event time capture feature provides a means of latching the time of an event input and/or generating a bus interrupt that is coincident with an external TTL pulse. The module can also be programmed to generate a periodic pulse rate/interrupt as well as
to generate a strobe/interrupt at a single predetermined time. 

Data Sheet

Real time clock
Bus request resolution: 100 nanoseconds 
Bus request latency: Zero
Major time format: Binary or BCD
Minor time format: Binary
Time code translator   
Time code formats: IRIG A, IRIG B (modulated or DCLS)
Modulation ratio: 3:1 to 6:1
Input amplitude: 500 mV to 5 V P-P
Input impedance: >10KΩ (AC coupled) 
Time code generator  
Time code format: IRIG B (modulated or DCLS) 
Output amplitude: 0 V to 10 V P-P (adjustable) 
DC level shift: TTL/CMOS 
Timing functions  
Heartbeat (TTL, 50Ω): Programmable periodic
2.3 mHz to 2.5 MHz

Time strobe (TTL, 50Ω): Programmable, 1mS through hrs 
Event capture (TTL, 50Ω): 100 nS resolution, zero latency 1PPSpulserate(TTL, 50Ω):
  Positive edge on-time 
Disciplined oscillator  
Frequency:  10 MHz

Outputs (50): 1, 5, or 10 MHz (selectable) 
Rate accuracy   
Standard oven oscillator: 2.0E-9 short term (tracking)
  5.0E-8/day long term (flywheeling)
Sync sources: Time code, 1PPS
VME Bus  
Size: 6Ux160 mm; B size, single
Address space:  A16, AM codes $29 and $2D, 64 bytes
Data transfer: D16

 D08(O), I(1-7), ROAK

Power: +5 VDC @ 1.5 A
  +12 VDC @ 50 mA
  +12 VDC @ 250 mA (GPS)
  -12 VDC @ 30 mA 
Temperature Module
Operating: 0°C to 70°C 
Storage: -50°C to 125°C
Operating: 5% to 95%*

PDF VME635091-SyncClock  Product Data Sheet