GPIB users/experts/programmers, step in here please

[N8YX]

WHOOOSH!

That's the sound of this thread going WAY over my head.

GPIB is an acronym for "General Purpose Instrument Bus". It's IEEE 488.2, and specifies a data-transfer standard by which laboratory instrumentation can be controlled.

A lot of the test equipment produced in the pre-USB/Ethernet days has a GPIB connector to facilitate programmatic control or step execution...data gathering and so forth.

Control logic is state-driven, meaning one piece of gear can wait on another to acknowledge an operation before it proceeds with a task.

Example: I have a Tek 5000-series plugin with a 50M40 relay card. I'm going to use one of the lines to switch the PTT circuit of a transceiver under test. Immediately after the relay controller signals closure, the main controller program commands a signal generator to generate a single-tone (1KHz) sine wave of 2.5mV amplitude...which is applied to the rig's Mic In connector.

Another instrument is then commanded to make power readings and yet another is commanded to study the RF output waveform. Should said waveform show signs of distortion (or other 'fail' criteria) the signal generator cuts its output and the relay card opens the PTT circuit, putting the device under test back into receive mode.

You've used an ATM before, right? They're all state-driven.

[X-Rated]

...

You've used an ATM before, right? They're all state-driven.

Wow. I didn't know many people around here have worked much with Asynchronous Transfer Mode.

http://en.wikipedia.org/wiki/Asynchronous_Transfer_Mode

[kf0rt]

I wonder if Arduino does GPIB.

Looks possible. Some thoughts on that here: http://arduino.cc/forum/index.php/topic,21821.0.html

[N8YX]

Wow. I didn't know many people around here have worked much with Asynchronous Transfer Mode.

http://en.wikipedia.org/wiki/Asynchronous_Transfer_Mode

Different ATM. ;)

[X-Rated]

Different ATM. ;)

D'oh. (_8(|)

[N1LAF]

GPIB is going extinct. It is basically an obsolete protocol. Most forward thinking hardware designers are using in-system reprogrammable devices, and replacing buses, like VME, GPIB, etc, with Ethernet. Ethernet as a bus essentially allows hardware independence. I good communications specifications using UDP/Multicast will be the direction to look in. At the local hardware level, intercopnnects using high speed SPI serial, which can move large words quickly with only 4 lines. Saves on board layout and complexity. Make hardware designs as generic as possible, digitizing inputs and recover outputs from digital sources, and make designs modular, high on reuse.

- In system reprogrammable FPGA's
- Programmable I/O devices, as Fred brought up, from Parallax
- Embedded processors, PIC's by Microchip.
--- PICs uses networks
--- PICs have hardware support for serial and USB
- Network as your system backplane
--- UDP for fast data transfer
--- Multicast, a variant of UDP, do not require live connections, and can be used by multiple devices simultaneously

I have seen, but not used, controllers that are built into RJ45 connectors, with I/O and built in web server. I really need to check these out.

[N1LAF]

Links:


http://www.lantronix.com/device-netw...ers/xport.html
http://www.lantronix.com/device-netw...servers/?tab=1 <<== Wireless network
http://www.embeddedarm.com/products/...ct=TS-7520-BOX
http://www.mosaic-industries.com/emb...icrocontroller

[X-Rated]

Nice.

[NY4Q]

Lordy. I used to program a lot of stuff via the ole trusty HP 9845...seems like a lifetime ago.

[N8YX]

The problem with "going extinct" is that there's a hell of a lot of (now affordable) test gear on the market that's GPIB programmable.

Most of this stuff is much better quality than comparable, late-model "hobby-grade" test equipment. Thus, it behooves the experimenter to extract the full potential of such.

Scariest thing I've seen in a long time? An Ethernet-connected, $200K DSO running embedded Windows XP. With nothing more than a running copy of BackTrack or a similar hacker's toolkit, I can destroy that instrument with little difficulty.

I'll take the older stuff, thank you very much.