I need a high precision, high resolution (thirty two bit) timer/counter for measuring real-time-clock crystal oscillators, using a GPS Disciplined 10 MHz external signal as the reference on one input and gating this over a couple of minutes on a second input. I was going to build one, but then came across the ADALM2000 and Scopy. Sadly there doesn't seem to be a counter/timer function provided.
Physics labs often use such counters for photon and geiger counting so a counter/timer function sort of fits with the project objectives.
I would think the hardware would have no problem doing this.
Are there any plans for this?
What would be required to program the ADLAM2000 to enable this functionality. i.e.
- Development environment
- Debugging hardware etc.
Currently you can build a Binary Counter with ADALM2000 and Scopy using the Pattern Generator (16bit).
Just group the digital channels and set the Pattern to "Binary Counter".
You can have a look at https://wiki.analog.com/university/tools/m2k/scopy/scripting-guide and build your own more complex functionalities.
Hope this helps.
Thanks for your prompt reply.
I don't think what you propose is what I need. I don't want to produce a binary count output. I want to input a signal into the device and clock the counter using this input. Then measure the count over a preset gate time. The counter would be a 32 bit counter implemented in the FPGA. It's only the count value divided by the preset gate time displayed via the Scopy Software that would be required. Digital output on the physical outputs is not required.
See the HP Agilent 53131A as an example of such a device.
I have attached a block diagram of a simple frequency counter to better explain what I need.
Also 16 Bits is insufficient resolution for measuring clocks to high precision i.e. part per billion.
Thirty two bits gives plenty of resolution at 0.233 parts per billion.
There are various modes this type of counter can be configured in:
- Manual start stop e.g. count events over an arbitrary period
- Clock gated start stop as per diagram.
- Internal and external timebase.
For high precision frequency measurement an external time base input from A GPS disciplined oven controlled oscillator is required. Most people can afford these. They usually come with a 10 MHz and 1 Hz output. For low frequency measurement of tuning for clock crystals at 32.762 k the 1 pps input divided down to a 32 seconds period provides adequate accuracy and resolution. In many cases a cheap GPS module with a 1 Hz output pulse would be good enough.
The frequency to be measured clocks the counter.