SCPI on a Linux Board - Letter of Intent

RE: SCPI on a Linux Board - Letter of Intent

akshitagupta15june — Sun, 24 May 2020 09:47:53 GMT

Have a look at my entry and please like and share #badass Woman Project Entry - Akshita Gupta

RE: SCPI on a Linux Board - Letter of Intent

Jan Cumps — Fri, 22 May 2020 19:17:48 GMT

This was an electronics-light project. Just plug a PiFace Digital on a Pi.

The result is quite useful in the lab though.

Here's an action photo of the project, where it switches a DMM between an OpAmp's input and output, time after time.

To measure the gain and dc offset 2000 times, under different conditions.

[View:/resized-image/__size/620x827/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7ff248f0-be34-4286-acc5-df716cbcdf65/2350.contentimage_5F00_206699.png:620:827]

RE: SCPI on a Linux Board - Letter of Intent

Jan Cumps — Sun, 27 May 2018 17:14:44 GMT

I've documented the first working version: SCPI on a Linux Board - Part 1: Proof of Concept

RE: SCPI on a Linux Board - Letter of Intent

Jan Cumps — Fri, 25 May 2018 20:47:01 GMT

Inspired by the BeagleBone Webcast series, I'm picking up this thread again (I have a few running in parallel these days [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7ff248f0-be34-4286-acc5-df716cbcdf65/5428.contentimage_5F00_1.png:16:16] )

I've installed the latest Debian on my BB and have just successfully cross-compiled and loaded a test program.

Here's an action shot of the active debug session:

[View:/resized-image/__size/823x480/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7ff248f0-be34-4286-acc5-df716cbcdf65/1351.contentimage_5F00_206698.png:823:480]

For this exercise, there should be no difference between the Raspberry Pi and BeagleBone for the SCPI library and network socket API.

It's only when talking to hardware that things will be different, but that's not the scope of this series.

RE: SCPI on a Linux Board - Letter of Intent

Jan Cumps — Sun, 29 Apr 2018 10:14:41 GMT

Some more progress: first contact from LabVIEW

[View:/resized-image/__size/699x299/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7ff248f0-be34-4286-acc5-df716cbcdf65/2727.contentimage_5F00_206694.png:699:299]

I don't have the reply working in the LabVIEW flow yet - it works different than serial/usb. But things look good.

RE: SCPI on a Linux Board - Letter of Intent

Jan Cumps — Sat, 28 Apr 2018 15:55:40 GMT

A few learnings from testing LabVIEW with another TCP/IP device (a Tektronix TBS 2000 oscilloscope - I won it in a contest [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7ff248f0-be34-4286-acc5-df716cbcdf65/contentimage_5F00_1.png:16:16] ):

I can get things to work with raw TCP/IP - not yet as a VISA instrument.

The Tektronix has all VISA drivers installed and I can contact it over VISA via TCP/IP, but not reliable.

With USB, that scope works just fine.

Have I opened a can of worms?

RE: SCPI on a Linux Board - Letter of Intent

Jan Cumps — Sat, 28 Apr 2018 13:49:28 GMT

Well, that didn't take long.

[View:/resized-image/__size/663x290/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7ff248f0-be34-4286-acc5-df716cbcdf65/contentimage_5F00_206693.png:663:290]

I have a SCPI parser running now that accepts SCPI commands and sends replies. Easier than I thought it would be.

Achievements unlocked:

program runs on Raspberry Pi, listens on a tcp/ip port for SCPI and can reply
SCPI library incorporated
cross compiled: developed on windows, executed on linux/Pi, debugged remotely from Windows

To do:

turn this into a daemon, with proper startup and shutdown
test on BeagleBone
make a test instrument. This is just a mock program pretending it's a digital multimeter.
implement SYSTem:COMMunicate:LAN:CONTrol? : dynamic allocation of control port.

RE: SCPI on a Linux Board - Letter of Intent

Jan Cumps — Fri, 27 Apr 2018 21:04:51 GMT

TCP/IP basics work on Raspberry Pi.

Compiled and debugged in Eclipse on a Windows 10 PC, compiled program executed on the Pi:

[View:/resized-image/__size/551x295/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7ff248f0-be34-4286-acc5-df716cbcdf65/contentimage_5F00_206691.png:551:295]

Inspiration: http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/server.c

This may not look spectacular, but I think it's cool that you can compile a C executable on a windows machine, transfer it to the Pi and step through the code in the debugger on that same windows machine - with 1 click on some button

RE: SCPI on a Linux Board - Letter of Intent

DAB — Fri, 27 Apr 2018 19:23:57 GMT

Good luck Jan.

DAB

RE: SCPI on a Linux Board - Letter of Intent

genebren — Fri, 27 Apr 2018 17:56:20 GMT

Good luck on your project!

Gene