Create a Programmable Instrument with SCPI - Part 1: Parser Library

RE: Create a Programmable Instrument with SCPI - Part 1: Parser Library

Jan Cumps — Sat, 01 Oct 2016 14:02:03 GMT

I've finished what I wanted to have. Full control of PWM signals with LabVIEW.

The design can independently control 7 double PWM modules.

Each module can have in-sync or complementary signals. The duty cycle of both signals can be controlled independently.

I can set a deadband on either of the two signals - with different times.

In LabVIEW, you can select one of the seven PMW modules, set the parameters and configure the device.

Here's a capture:

[View:/resized-image/__size/620x250/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-aaa8ee77-3c04-417d-b592-efa648d5fde7/7446.contentimage_5F00_185991.png:620:250]

The signals on the scope are the two outputs of PWM module 1.

Both are at 50% duty cycle.

There's an asymmetric deadband applied. It's longer for the rising edge of the blue signal. (The purple trace shows the deadband).

RE: Create a Programmable Instrument with SCPI - Part 1: Parser Library

Jan Cumps — Sun, 25 Sep 2016 17:51:11 GMT

added Create a Programmable Instrument with SCPI - Part 5: First Hardware Commands

It's getting real now.

RE: Create a Programmable Instrument with SCPI - Part 1: Parser Library

Jan Cumps — Sun, 25 Sep 2016 15:08:57 GMT

This isn't spectacular yet, but I have the first command working:

Turn on or off PWM channel 1:

[embed:dc8ab71f-3b98-42d9-b0f6-e21e02a0f8e2:3ef06e6b-9b7d-4651-b12d-db8be7f5e991:type=text&text=PWM1%3ASTATe+ON%0APWM1%3ASTATe+OFF]

[View:/resized-image/__size/960x540/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-aaa8ee77-3c04-417d-b592-efa648d5fde7/contentimage_5F00_185990.gif:960:540]

RE: Create a Programmable Instrument with SCPI - Part 1: Parser Library

Jan Cumps — Sat, 24 Sep 2016 09:48:46 GMT

I've posted Create a Programmable Instrument with SCPI - Part 4: Error Handling by Default

It shows how the open source SCPI library supports extendable error handling by default.

RE: Create a Programmable Instrument with SCPI - Part 1: Parser Library

Jan Cumps — Mon, 19 Sep 2016 15:34:50 GMT

I've posted part 3: Create a Programmable Instrument with SCPI - Part 3: First Conversation *IDN?

With source code. This concludes the pure software and infrastructure part. I can start implementing real functions that do something electronically (PWM generation)

RE: Create a Programmable Instrument with SCPI - Part 1: Parser Library

Jan Cumps — Sun, 18 Sep 2016 08:30:30 GMT

I've posted part 2: Create a Programmable Instrument with SCPI - Part 2: Serial over USB

RE: Create a Programmable Instrument with SCPI - Part 1: Parser Library

DAB — Sat, 17 Sep 2016 19:41:39 GMT

Nice post Jan.

I had always been interested in using something like labview, but just never got around to it.

The systems designs I had been doing were at a scale much larger than anything like labview was intended to support.

So I will be following along with great interest. You just never know when you learn something important.

DAB