Hobby Components Logic Analyzer not working above 4MHz (HCTEST0006)

Forum for posting topics and questions about anything.
Post Reply
andyowenwest
Posts: 2
Joined: Thu Feb 24, 2022 1:34 pm

Hobby Components Logic Analyzer not working above 4MHz (HCTEST0006)

Post by andyowenwest » Thu Feb 24, 2022 1:53 pm

Order Details: TGFKFEZDM Placed on 02/22/2022 18:07:17

This is the second analyzer Ive bought - the first being sourced from ebay so I re-purchased direct incase of any differences.

Both analyzers work correctly with sigrok/pulseview at 4MHz or below

However above this sample rate there are two strange behaviours

1. If a trigger is set
When hitting the run button after around 1 second acquisition stops (without trigger event happening)

2. If a trigger is not set
Only a partial acquire happens. For example setting 24MHz with 50MSamples should result in around 2 Seconds worth of data. Only around 200mS is acquired before 'auto stopping'

Just out of curiosity I also tested this in Saleae Logic which has the same behaviour above 4MHz and also results in a 'Read Timeout' error

The advert for these analysers does mention:

*Sampling rates at 4MHz and above will be dependent on system performance including the speed of your computer and the USB interface it is connected to.


However I have tested on 3 PCs all of which are high spec machines i5/i7, 16Gb Ram, SSD, USB3.0 and all PCs result in the same behaviour with both analyzers

Ive also noticed the analyzers fairly frequencltly disconnect and reconnect as if the USB cable has been pulled and re-inserted by itself. Ive also tried multiple USB cables

Questions are:

1. Is the USB cable that the unit ships with sufficient for 24MHz
2. Exactly what PC requirements are needed for +4MHz performance
3. Any special setup required for +4MHz performance?

Environment on my main machine is:

Windows 10 PRO x64 Version 10.0.19042 Build 19042
Processor Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz, 2501 Mhz, 2 Core(s), 4 Logical Processor(s)
Installed Physical Memory (RAM) 16.0 GB

SigRok: Latest nightly build
Pulseview: Latest nightly built

Driver: WinUSB v6.1.7600.16385, Installed with ZaDig
Device Manager: Device recognised as FX2LAFW

andrew
Site Admin
Posts: 1374
Joined: Sun Aug 05, 2012 4:15 pm

Re: Hobby Components Logic Analyzer not working above 4MHz (HCTEST0006)

Post by andrew » Thu Feb 24, 2022 5:12 pm

1. If a trigger is set
When hitting the run button after around 1 second acquisition stops (without trigger event happening)

2. If a trigger is not set
Only a partial acquire happens. For example setting 24MHz with 50MSamples should result in around 2 Seconds worth of data. Only around 200mS is acquired before 'auto stopping'

Ive also noticed the analyzers fairly frequencltly disconnect and reconnect as if the USB cable has been pulled and re-inserted by itself.
It's likely that these are all symptoms of the same issue...

1. Is the USB cable that the unit ships with sufficient for 24MHz
Yes, although we have seen bad USB cable causing issues like you have reported in the past. Trying a different USB cable would have been my first suggestion although as you have already done that I guess that's not the cause.


2. Exactly what PC requirements are needed for +4MHz performance
It's not so much the performance of the processor (yours sounds more than adequate), but rather general system performance and in particular the performance of the USB interface. Thinks like USB hubs, other devices plugged into the same hub (or internally sharing the same USB root connection) or long USB cable runs from external hubs could cause a problem.

Failing this if you're using a laptop check for any USB power saving options.


3. Any special setup required for +4MHz performance?
Not really, just the above considerations.
Comments made by this poster do not necessarily reflect the views of Hobby Components Ltd.

andyowenwest
Posts: 2
Joined: Thu Feb 24, 2022 1:34 pm

Re: Hobby Components Logic Analyzer not working above 4MHz (HCTEST0006)

Post by andyowenwest » Fri Feb 25, 2022 11:29 am

Thanks for the response.

I think this may be a Windows 10 issue - Has anyone from hobby components verified 4MHz+ on Windows 10 x64?

I think for future users It would be worth putting together a definitive guide on steps required to get that performance on Win10 as out of the box 4MHz seems to be the limit - please correct me if anyone else has had a different experience?

I have built sigrok / pulseview from source on linux on the same machine and the acquire is working correctly

In answer to your suggestion about USB power settings I have made sure selective suspend is disabled in power plan - Is there any other changes needed?

andrew
Site Admin
Posts: 1374
Joined: Sun Aug 05, 2012 4:15 pm

Re: Hobby Components Logic Analyzer not working above 4MHz (HCTEST0006)

Post by andrew » Fri Feb 25, 2022 3:27 pm

I think this may be a Windows 10 issue - Has anyone from hobby components verified 4MHz+ on Windows 10 x64?
I've just pulled one out of our current stock and tested it at the maximum sample rate and it seems to be running fine. I.e., at 24MHz over 1GS/s it ran the full sample period of just over 40 seconds with no issue. This was on a 64 bit Windows 10 pro desktop. Note that I didn't set any triggers or decoders. But for reference here is the system spec of the computer I tested it on:

AMD Ryzen 3 1300X quad core
Gigabyte AB350 gaming 3 motherboard
16GB DDR4 RAM

So as mentioned previously your system should be more than adequate to run at the maximum sample rate so I don't think it's that. After ruling out a bad USB cable/connection it's more likely to be some piece of USB hardware or something in Windows that interfering with the connection.

In answer to your suggestion about USB power settings I have made sure selective suspend is disabled in power plan - Is there any other changes needed?
No additional system settings I can think of. I just mentioned that as some laptops have a tendency to enable USB low power settings by default. The only other thing I can suggest at the moment is removing any other USB devices currently plugged into your computer that you don't need. Just in case one of those is interfering with the connection.
Comments made by this poster do not necessarily reflect the views of Hobby Components Ltd.

Post Reply

Return to “General Discussion”