Thanks so much, your description of collecting the raw timing data is
really clear. I like the technique of doing timing interval
measurements from a slower known reference on one channel to a DUT on a
second channel. This definitely gets me started.
jeff
Didier Juges wrote:
Jeff,
I
Jeff Mock wrote:
Thanks so much, your description of collecting the raw timing data is
really clear. I like the technique of doing timing interval
measurements from a slower known reference on one channel to a DUT on a
second channel. This definitely gets me started.
jeff
An
You will need a clock shaper to convert the sine to a digital signal, and a
series of dividers.
You can look at my page on clock shapers for ideas:
http://www.ko4bb.com/Timing/ClockShaper.html
If you look through the archives, I believe earlier this year there was a
thread about the
Jeff
If you do a web search for frequency divider or standard, there are
several good home brew type projects that are relatively simple and
straight forward.
Below are some of the sites I have visited. The first 2 explain more on
the tech end and the last is a public domain schematic of a
Hi Jeff:
Another way is using a PIC micro controller, see:
http://www.prc68.com/I/PRC68COM.shtml#TVB
http://www.leapsecond.com/tools/PPSDIV.ASM
Have Fun,
Brooke Clarke
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam
jshank
I would like to convert a 1 MHz sine wave to a 1 pps TTL.
I'm assuming you aren't too concerned about jitter.
There are two issues. The first is converting your sine wave into a valid
logic level. The second is dividing by a million.
If your sine wave has a reasonable amplitude, I'd just
Hal Murray wrote:
I would like to convert a 1 MHz sine wave to a 1 pps TTL.
I'm assuming you aren't too concerned about jitter.
There are two issues. The first is converting your sine wave into a valid
logic level. The second is dividing by a million.
If your sine wave has a
Hi Gang!
I just bought a Prologix GPIB - USB converter model, version 5.00,
and I am having some problems. It works fine on some of my instruments,
but it just locks up when I hook it to an HP3478A DVM. The DVM is
known good, and works great with my HP85B (doesn't everything?).
Basically, if I
Chuck,
I have used my HP 3478A with my Prologix controller (and several other GPIB
controllers), but I have not upgraded the firmware to 5.0 (I think I am
still at 4.61 or something like that). I will try and let you know.
The 3478 is a relatively recent instrument (as far as GPIB
Hi Chuck:
It may be timing. The 85 and the 3478 are old and slow. Have you tried adding
wait statements after you send any command to give the 3478 time to think
about it? Also it may be good to send CRLFEOI after each command then do
the wait.
Have Fun,
Brooke Clarke
Hello Chuck,
It appears that 3478A sends data continuously as soon as it is addressed to
talk. Since the Prologix adapter is busy processing GPIB data it is unable
to respond to USB commands.
One solution is to turn read-after-write off (++auto 0) before connecting
the adapter to 3478A, and
On Tue, 27 Nov 2007, Prologix wrote:
Hello Chuck,
It appears that 3478A sends data continuously as soon as it is addressed to
talk. Since the Prologix adapter is busy processing GPIB data it is unable
to respond to USB commands.
One solution is to turn read-after-write off (++auto 0)
Chuck,
Sending
++addr 09;
++read 10;
with my Prologix to the HP 3478A returns a single reading just fine.
Didier KO4BB
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Chuck Harris
Sent: Tuesday, November 27, 2007 9:34 PM
To: Discussion of
Some instruments are pretty hard headed and can't be easily convinced to
stop after just one piece of information.
So Abdul implemented the ++read command.
I know some people like that :-)
Too bad ++read does not work with those...
Didier KO4BB
-Original Message-
From: [EMAIL
Prologix wrote:
One solution is to turn read-after-write off (++auto 0) before connecting
the adapter to 3478A, and then use ++read command to read one measurement at
a time. Please see the manual (www.prologix.biz) for ++read command options.
I nearly always turn off auto mode on the
Hi Brooke,
I'm sending the commands as I type them in Kermit. Surely that is slow
enough.
I cannot send any commands to the 3478A. The simple act of asking the
prologix to do anything other than ++ver, locks up the prologix so it
ignores all USB traffic.
The Prologix works fine with a 3438A,
Chuck,
The commands I copied in my previous post were sent very fast. My program
sends the strings automatically when I click on a button, so fast timing is
perfectly acceptable by the Prologix/3478A combination.
Let me know if you need me to give you any particular configuration
information of
Bruce Griffiths wrote:
Jeff Mock wrote:
Thanks so much, your description of collecting the raw timing data is
really clear. I like the technique of doing timing interval
measurements from a slower known reference on one channel to a DUT on a
second channel. This definitely gets me
Did you try sending ++auto 0 before powering up the 3478A?
This setting is persistent, so you should only have to do it once to keep
the board from automatically addressing the 3478A to talk.
Also try disconnecting any/all other RS-232 devices from your PC during
initial testing, and/or try a
Hello Jeff,
Thanks for the compliments. Much appreciated.
You may configure the Prologix adapter (using ++eot_enable and ++eot_char)
to send (append, really) a user-specified character to USB ouput when it
detects EOI. By checking for the character you can determine if EOI was
asserted.
Prologix wrote:
Hello Chuck,
It appears that 3478A sends data continuously as soon as it is addressed to
talk. Since the Prologix adapter is busy processing GPIB data it is unable
to respond to USB commands.
I don't think the 3478A is sending anything at all.
If it was, it should be
In a message dated 11/27/2007 21:22:41 Pacific Standard Time,
[EMAIL PROTECTED] writes:
Under what criteria does the Fury turn on its lock light?
Hi CH,
good question, let me CC the time nuts on the answer.
We are at the PTTI, so sorry for the sluggish communication.
The Fury actually
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