🚀 go-pugleaf

On Sat, 09 Feb 2002 05:56:34 GMT, DeductThisPart.gpsnav@pacific.net.sg
(Tom Werry) wrote:

>
>Peter,
>
>>Will do - it's on another box elsewhere.  Probably in about 20 hours from 
>>now I can post some of it ...
>
>Okay - are you east or west - Sydlley I think is 5 hrs ahead of
>Singgers, Perve is about the same as me?


Perth - GMT+8.  Siddley is 2 (3 when they go silly) ahead of me.

>>Yes, and it isn't sending a cracker.  That's the problem - all the SCPI 
>>commands I saw  resulted in data in the HP output port, but I couldn't find 
>>an SCPI command to force it to actually Tx any data ..
>
>Sounds like all the obvious stuff is okay - are you saying that the
>(HP?) it is not sending and not that the (PC?) it is not sending?  And
>that therefore your PC stuff may all be okay?

The commands I am sending are basically (no pun intended) out of the
VBA/XL7 example in the userman.  They are just string commands.
Unfortunately the only examples they give are the VBA/XL7 and C - and
I don't speak C :-((

The first command sent/received causes the HP to go into remote mode -
which is part of the correct response.  I sincerely believe the PC end
to be sound.

Since I posted previously, I found a QB example in the HP34901 manual.
(The 34970 is really a 34901 DMM with a three-mux-card extension).
Tried that with no greater success.  In fact, it gives an "invalid
separator/delimiter" error after a certain number of commands are sent
- almost like it is concatenating them and getting an overflow.

>>You speak SCPI?
>
>Unfortunately I don't know what on earth SCPI is - I can just get the
>PC side sorted out for you once you get the HP to send data.

SCPI is Standard Commands for Programmable Instruments - sort of an
industry standard which HP stick to albeit not religiously.

>I apologize if I shouldn't have answered this, not knowing SCPI, but
>if it is any kind of a PC/QB serial problem, I have probably done more
>work with that than anyonbe else on the planet when it comes to
>connecting to all kinds of other serial devices like data loggers,
>sensors etc.

No apology needed.  I welcome your input.  I also have a long history
in sorting (usually other people's) RS232 interfacing problems on all
sorts of gear - including building custom interfaces when required.
Some bizarre things such as a bidi C64 to a LA35 DECwriter which had
only a current loop interface.

>Is it possible that HP is waiting for a control line to go on from the
>PC side, or for the PC to send an initial XON or something dopey like
>that, before transmitting any data?

Assuming it IS actually receiving the commands and interpreting them
correctly, it MUST be waiting for SOMETHING ...

I started using XON/XOFF (which is the HP factory default) and sent
one after a couple of setup commands, but didn't seem to make any
difference.  I then tried RTS/CTS and finally set up the HP to "no
handshake".  All to no avail.

I am still suspecting that it has data in its o/b but isn't sending.
Handshake lines are all connected.  The 9M/9M cable is:

1 (DCD) straight
2/3 crossed (TxD/RxD)
4/6 crossed (DTR/DSR)
5 Gnd - straight
7/8 crossed (RTS/CTS)
9 straight (RI).

This is the standard HP cable supplied for the instrument for DTE-DTE
use.

>To verify that QB is not doing something stupid for you, can you
>(easily?) try hooking the HP up to a terminal program like the old
>CROSSTALK or similar, or possibly Windows hyperterminal without
>getting too bogged down in that as a separate exercise?  This used to
>be an easy way for me to sort stuff out on occasion.

Can't do the Windoze thing on this box.  Could drag another box down
there I suppose.  But I know exactly what QB is sending.  I can see
the LEDs on the breakout box for all lines of interest.  Data goes but
no flicker on the HP TxD line.  It simply aint talking.  When it does
send a string I can certainly interpret/dismember it.

I see these possibilities:
(a) the HP is ignoring me, or at least ignoring enough commands to
frustrate bidi communication.
(b) I'm not sending the "magical" command/handshake/? to get it to
send data.
(c) the HP is broken

.Peter