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Products => Test Equipment => Topic started by: conducteur on July 27, 2020, 09:37:05 pm

Title: multiple channel logic generator
Post by: conducteur on July 27, 2020, 09:37:05 pm
We all know what a logic analyzer is, but does the opposite exist? A generator that can generate certain test patterns (serial/parallel) on TTL, LVTTL, ...
There are some boards that may be able to do this to some extent (dangerous prototype bus pirate, red pitaya, or just a simple arduino like board with a mcu) and Ebay only shows a few 1000$+ second hand devices.

More and more things use digital electronics, or are even implemented digital with dsp in a digital way rather than analog, so I wonder why this is such a niche product?
Title: Re: multiple channel logic generator
Post by: ebclr on July 27, 2020, 11:43:21 pm
For sure

https://www.digikey.com/en/product-highlight/d/digilent/digital-discovery?utm_adgroup=General&utm_source=google&utm_medium=cpc&utm_campaign=PT_RLSA_Cart%20Abandoner_Dynamic%20Search&utm_term=&utm_content=General&gclid=CjwKCAjw9vn4BRBaEiwAh0muDB9Gr3KnGXpqcuA3lHH_1cejFszp3MBcMt2bFLoN1FeYQPuS2bnJ7hoCL30QAvD_BwE (https://www.digikey.com/en/product-highlight/d/digilent/digital-discovery?utm_adgroup=General&utm_source=google&utm_medium=cpc&utm_campaign=PT_RLSA_Cart%20Abandoner_Dynamic%20Search&utm_term=&utm_content=General&gclid=CjwKCAjw9vn4BRBaEiwAh0muDB9Gr3KnGXpqcuA3lHH_1cejFszp3MBcMt2bFLoN1FeYQPuS2bnJ7hoCL30QAvD_BwE)
Title: Re: multiple channel logic generator
Post by: conducteur on July 28, 2020, 01:48:46 pm
But that's similar to the examples I already mentioned and not a standalone device.
Title: Re: multiple channel logic generator
Post by: Henrik_V on July 28, 2020, 02:25:28 pm
Since you need more configuration, all solutions I know work together with external PC/Software ...
I could use the 16 bit  LVDS output of 'my' NI-PXI-5422 200MHz AWG  and I'm shure some other AWGs have digital outputs too .. even as standalone..
 

Title: Re: multiple channel logic generator
Post by: Kean on July 28, 2020, 03:58:38 pm
Maybe a Keysight 81134A Pulse Pattern Generator suit your needs?   >:D
Title: Re: multiple channel logic generator
Post by: guenthert on July 28, 2020, 04:24:40 pm
We all know what a logic analyzer is, but does the opposite exist? A generator that can generate certain test patterns (serial/parallel) on TTL, LVTTL, ...
There are some boards that may be able to do this to some extent (dangerous prototype bus pirate, red pitaya, or just a simple arduino like board with a mcu) and Ebay only shows a few 1000$+ second hand devices.


  I also would have mentioned Digient's Analogue Discovery (2) (not cheap, but much less than $1000).  When working with digital systems, not having a computer around seems rather silly.

  Of course there are companies which cater to every desire and are happy to sell you pattern generators.  If it doesn't have to be all that fast, then those old, clunky LA from HP can be acquired for little money and some (a specific model from the series, but others might be upgraded) offer a pattern generator option.

More and more things use digital electronics, or are even implemented digital with dsp in a digital way rather than analog, so I wonder why this is such a niche product?
  Where have you been the last 40 years?  I rather think that parallel buses are an exception today (and have been for at least 20 years).  Communication between MCUs or between MCU and ADC will more likely be serial (and then you'd rig one of the MCUs to prototype/debug, rather then introducing yet another component, wouldn't you?), for faster buses it will be FPGA instead of a MCU.  I can't see much use for a patter generator there, I'd rather would want a protocol simulator then.
Title: Re: multiple channel logic generator
Post by: conducteur on July 28, 2020, 06:03:48 pm
Busses are serial indeed, but systems can have many inputs...
Title: Re: multiple channel logic generator
Post by: RomDump on July 28, 2020, 07:10:14 pm
We all know what a logic analyzer is, but does the opposite exist? A generator that can generate certain test patterns (serial/parallel) on TTL, LVTTL, ...

The Technical name is Digital Pattern Generator. Many companies make them as was mention previously.

You asked for one under $1000 

http://www.saelig.com/WGP/LA034.htm (http://www.saelig.com/WGP/LA034.htm)
Title: Re: multiple channel logic generator
Post by: free_electron on July 28, 2020, 07:11:50 pm
such a thing is called a pattern generator.
has been in existence for a long time.
HP 16720 board for the logic analyzers.
Title: Re: multiple channel logic generator
Post by: doktor pyta on July 29, 2020, 07:37:38 pm
@conducteur

I wonder what was Your way of thinking that pushed You to ask this in Metrology section.

BR
Title: Re: multiple channel logic generator
Post by: conducteur on July 30, 2020, 03:14:15 pm
This is indeed not the best category, it may be moved to Test Equipment section...
Title: Re: multiple channel logic generator
Post by: srb1954 on July 31, 2020, 09:08:55 am
Look for an HP 8175A.

It does 24 channels parallel data or 2 channels serial data with options for TTL/CMOS/ECL output levels.