🚀 go-pugleaf

budgie <budgie@nowhere.cantech.net.au> wrote:

>UPDATE:

>It turns out that to get the HP instrument to actually interpret and
>act on commands, the OPEN COM has to include the LF parameter.

Peter,

What?  You mean you weren't adding a CRLF pair of bytes to the end of
each command you sent?  I'll have to add this to my list of silly
things not to omit which I went thru with you before, hahaha - if I'd
thot of it before it would have been there in my list, but I just do
this so automatically for any controlled device that I forgot it.

I find it never screws things up if you put it in and it is not
needed.  My output statements ALWAYS have CRLF added explicitly and
end with a semi-colon - then there's no doubt about what's going down
the wire.  You also have to be careful, some dipshit devices actually
want to see these 2 chars. the other way round!!!???

Just a note about another way I sometimes use to sort out the
undocumented or misdocumented stuff sometimes:

If there is a sample controller program that comes with a unit that
you can run on a PC, and it starts the unit okay but you cannot do the
same with your own code which you wrote to improve upon the
controller, then you use a "piggy-in-the-middle" program and another
PC with 2 serial ports to scope out what their program is doing.

(If you check their web site you might find such a test program from
HP if there wasn't one in the box).

You wire this second PC in between the PC running the supplied sotware
and the device with a second cable that duplicates the one supplied.

This PITM program transfers every byte in one port out the other, for
both ports.  On the way by, it records all bytes going both ways in a
file or two, depending on how you feel about interspersed bytes on
bi-directional comms.  You might want to wait for a CRLF on each port
before recording the accumulated line for that machine.

If you also wosh to display the bytes/msgs on screen on the way by,
you must filter the control codes that will beep & scroll the scree -
or just ignore these as it is running, depending on how much screwing
around you want to do as opposed to just solving thew immediate
problem.

I've sorted out a few troublesome situations with the
"piggy-in-the-middle" and gotten a few raised eyebrows from smartass
manufacturers reps. in the process.

 - Tom