Thank you, Harvey.
If I understand correctly, you're saying that the # GPIB connection may
"port" another, "hot swapped" instrument to the same # GPIB?
I got impatient after posting this and thought I'd play with it a little
more and I connected the GPIB interface to the TDS754D then booted it and
it just landed on #4 GPIB. Not sure why on #4 (whether it had to be
"elevated" at #4 and why there's three below that having nothing
connected). Generally speaking, I'm seeing different instruments landing on
a pretty wild "#" GPIB port. I'm always doing a "list" to inquire which
GPIBs have something attached.
Radu.
On Sat, Mar 22, 2025 at 6:54?PM Harvey White via groups.io <madyn=
[email protected]> wrote:
The 488 bus is an addressed bus, which means recognizing an address on a
bus and having something respond (think I2C for an example).
So when you hot swap instruments, assuming that you don't glitch
something, then an existing address doesn't respond, and a new address
doesn't yet get recognized.
The controller (and I think it doesn't , unlike USB) start a new connect
sequence. You'd have to program it.
That means, to autoconnect, you'd need to be polling the interfaces (all
of them), and when one doesn't respond, you need to forget it. You then
need to scan for a new device. (and 488 has, IIRC, none of that),
although the controller by polling each device.
So somewhat different there, and not like USB.
Harvey
On 3/22/2025 7:47 PM, Radu Bogdan Dicher via groups.io wrote:
Hi all,
As I'm exploring GPIB in my environment on multiple instruments, a
newbee question - is GPIB essentially hot swappable?
Differently put, can I typically just hook it up to an instrument that's
running and expect it to smoothly connect? Or is it typically better to
connect GPIB while the instrument is off, then turn it on, so it'd scan its
"peripherals" during the booting sequence and this would guarantee it's
connecting with no issues?
I assume there's a rule of thumb, instead of a situation where maybe all
instruments may be different and it's hard to tell what's the best approach.
I've connected it plenty before, but 95% of the time it's been hooked up
to one instrument and so "hot swapping" wasn't a consideration.
This is for a TDS754D, reason I'm posting on this board, but I'm looking
for some input applicable to any instrument/brand.
Thank you,
Radu.
