Hi John,

Can you share with the group any interesting applications this
new processor board has enabled?

Other than turning the 5370A into a capable replacement for the
5370B...

-Chuck Harris

John Seamons wrote:

On 10/8/2014 8:46 AM, Chuck Harris wrote:

?

I believe the only significant difference between the A and B is that
the B had a slightly more robust input module, and came standard with
the 10811 OCXO.

There were some firmware differences related to GPIB handling, but the
"B" firmware works in the "A". I posted instructions a while back -
http://www.flatsurface.com/5370A/

Hi Chuck,

The benefit is that you can use Ethernet straight into the 5370, you can
get much higher sampling rates and well, we can have fun hacking up more
functionalities into the 5370 native support if we like to.

Cheers,
Magnus

On 10/08/2014 02:46 PM, Chuck Harris wrote:

Hi Mike,

The B is significantly faster in handling the GPIB interface,
and other internal processor functions than the A... and John's
board levels the playing field quite nicely.  My 5370A runs much
more quickly using John's board.  I run the "B" firmware on my
"A" counter.

The input module changes are largely irrelevant to most users.

-Chuck Harris

Mike S wrote:

Hi Magnus,

As one of the charter users of the board, I know that.  I was hoping
that some of the other users might elaborate on what John's board has
done for them that they wouldn't have done otherwise.

The addition of a BBB inside of a 5370 just reeks of future capabilities,
and possibilities.  How have these opportunities been exploited?

I quite enjoy being able to run my 5370 in the lab when I am in my
office... but that is a luxury, not a need... for me.

-Chuck Harris

Magnus Danielson wrote:

I'll introduce another angle to the discussion:

How have others handled bringing the USB or Ethernet
interface outside of their 5370?  There aren't exactly any
extra holes in the back panel to run the cables through.

Is removing the HPIB connector "the way"?

Is anyone making a replacement panel that has a USB
and an RJ connector mounted?

I don't like leaving the lids off of my test equipment.

-Chuck Harris

Magnus Danielson wrote:

On 10/8/2014 9:52 AM, Chuck Harris wrote:

Why would that be? They use the same speed processor, and the GPIB
interface is unchanged.

Hi Mike,

I can't say why, but both my experiences, and HP's manuals
and catalogs say that it is the case.

HP5370A 6000 samples/sec fast binary mode
10-20 readings/sec full format HPIB

HP5370B 8000 samples/sec fast binary mode
10-20 readings/sec full format HPIB

Everything is definitely peppier using John's board than
either a B or A.

-Chuck Harris

Mike S wrote:

I plan on removing the rear panel and making appropriate size holes on a
mill

for USB connectors something like
http://www.l-com.com/usb-panel-mount-usb-cables?cmp=011413

I will be using a shielded connector, same with the RJ45 connector
http://www.l-com.com/ethernet-ecf-panel-mount-cat5e-rj45-jack-110-punchdown-style

only using L-Com's site as a reference, in no way promoting them.

In some of the industrial work I've done, I have used this type of
connector/housing http://www.te.com/catalog/feat/en/c/20122

If you don't care about stuff radiating from your USB and Ethernet
antennas, on the E just search "panel mount (USB,ethernet)"

-pete

On Wed, Oct 8, 2014 at 7:00 AM, Chuck Harris cfharris@erols.com wrote:

In message 54354378.8020102@erols.com, Chuck Harris writes:

I ran mine out though a slightly enlarged ventilation hole
in the right hand side panel.

--
Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG        | TCP/IP since RFC 956
FreeBSD committer      | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

One future project would be to replace the front panel with a LCD/Touch
Panel

On Wed, Oct 8, 2014 at 6:56 AM, Chuck Harris cfharris@erols.com wrote:

On Oct 8, 2014, at 8:00 AM, Chuck Harris cfharris@erols.com wrote:

I have looked into the mechanical issues of doing that, but haven't done a PCB layout yet.

My plan was to include a USB isolation chip on the board so the USB connection has as much galvanic isolation as the transformer-coupled Ethernet. Also, I wanted to add a regulator to supply +5 on the internal side of the USB, driven from one of the large caps of the HP supply. That would provide some hold-up power for orderly shutdown of the Beagle on 5370 power-off. Alternatively, there would be some jumpers so the USB could bypass the isolator so the USB power could be supplied full-time from an external USB charger. That way the Beagle would run continuously for an "instant on" experience on 5370 power-up.

There are some EMI/EMC and ground loop issues with all this. My guess is that if you use shielded Ethernet cable the shield/drain wire, and the shield/gnd wire of the USB,  should probably be left floating on the 5370 end (i.e. non-shielded USB/RJ45 connectors on the PCB or making sure shielded connectors are isolated from the back panel). But I am no expert with such issues and would appreciate any advice. I kinda like PHK's solution: use a hole to get the cables out of there as quickly as possible.

On Oct 8, 2014, at 6:46 AM, Chuck Harris cfharris@erols.com wrote:

I haven't done much of interest beyond the high speed binary-mode-over-Ethernet hack (about 39K meas/sec last time I checked). I'm not even sure how useful that is in a time-nut context.

There are lots of possibilities though. Adding a timestamp counting mode would be pretty nice assuming you could get NTP on the Beagle working well. There is some code that allows a user application to generate content for the little integrated web server. So creating some plots on the instrument itself would be pretty easy (right now a browser connection shows you the display & LEDs and accepts virtual button pushes).

Hi

You probably are better off doing time stamping relative to the 5370’s timebase than doing it relative to an external standard. Adding another error into the mix (NTP variability) is not going to help anything. All you really need is a “start of file” time/ date and a number that represents time since start of file.

Bob

On Oct 8, 2014, at 2:05 PM, John Seamons jks@jks.com wrote:

John,

Time-stamping is wonderful. But note -- it does not imply using NTP! Best to time-stamp with some sort of fine nanosecond or picosecond XO or OCXO or Rb or Cs or GPSDO -- and not against the gross millisecond or microsecond PC / SBC / hardware / software cauldron of NTP.

/tvb

At that point, why not just remove the few remaining HP parts and put them in a new enclosure? :)

On Oct 8, 2014, at 1:36 PM, "Tom Van Baak" tvb@LeapSecond.com wrote:

Okay, then I didn't quite understand that requirement of time-stamping.

I made a real mistake by not running the 5370's 10 MHz oven clock, that was available right there on a processor board pin, to a GPIO on the Beagle so it could be accurately counted with the built-in event counter and software overflow (that clock used to drive the processor clock of the old MC6800). A terminating resistor and level-shift are required if I remember correctly, so it would be slightly more effort than a "blue wire" fix.

Hi

The purpose of time stamping: You sample the phase of a signal and log the time at which you recorded the phase.

If you then want frequency, you can take the delta time between stamps and the delta phase between stamps and get frequency. If both time and phase are very accurate, the resulting frequency estimate will be accurate as well.

Some examples:

Taking a PPS output and time stamping it to picoseconds is one way to do this. It is always a zero phase (rising edge for instance), so it drops back to a delta time measure.

Looking at a 10 MHz sine wave with a counter is another way to do this. You likely also have a zero crossing, so again it’s a measure at zero phase, time stamped to picoseconds (or what ever).

It both of the cases above, your instrument actually reads out a “delta time” between the edge / zero crossing any your time stamp. If you look at the delta time as a phase, then you do have phase / time stamp data.

If you have a system that samples a beat notes out of a DMTD system (say with a good ADC), then you can indeed have a true phase number.

The whole “is it delta time or delta phase” is one of those things that can be caught up on in by reading several dozen papers that argue the terms back and forth. The result is that common usage is to call it phase.

Bob

On Oct 8, 2014, at 4:26 PM, John Seamons jks@jks.com wrote: