GW Instek GDS-3000 scope bandwidth hack - Page 1
Forum section: electronics / testgear

author: meppr
author_rank: Newbie
timestamp: March 10, 2022, 12:05:48 am
content: This might not be of interest to anyone, but just in case…The GDS-3000 scopes were launched a decade or so ago, with a choice of 2 and 4 channel models at 150Mhz/250Mhz/350Mhz up to 5GS/s and 500Mhz up to 4GS/s. The GDS-3152 was the bottom of the range model (150Mhz 2 channel), but it still offered 1 x 2.5GS/s or 2 x 1.25GS/s.The range was also sold under the Iso-Tech brand with IDS rather than GDS model naming, but the same numbering scheme.All except the 500Mhz models seem to have been discontinued some time back. I suspect that the 500Mhz has slightly different hardware, but that the lower models are all essentially the same (possibly with an extra ADC in the 2-channel 350MHz). There was no bandwidth upgrade option AFAIK, so if you had a 150 or 250Mhz model you were stuck there.However these run an old Linux variant, with telnet available, and looking around it seems there's a 1-byte file in the /home/dso folder which determines the model and bandwidth. The value of this byte appears to correlate to models as follows (though I've only been able to test the first 4):00 : GDS-315201 : GDS-325202 : GDS-335203 : GDS-350204 : GDS-315405 : GDS-325406 : GDS-335407 : GDS-3504I tried editing it on an Iso-tech IDS-3152 and was able to change the reported model to IDS-3252 or IDS-3352.More importantly : with the latter it was pretty much flat out to 350Mhz with the -3 dB point just past 400MHz. The decent sample rate makes this interesting compared to similar hacks on some other scopes.I was also able to change it to the ‘500Mhz’ IDS-3502, and it reported as such but there was no actual improvement over the 350Mhz config.The current firmware has telnet access enabled; if networking is set up (Utility button) it's easy to get command line access, for example:Code:telnet 172.16.5.195 23Log in as root (the password is the same on more recent GW Instek scopes so can be readily found by searching this forum...)First make a backup copy of the bandwidth conf file, more out of good habit than necessity:Code:cp /home/dso/bwconf /home/dso/bwconf.bakThen change the model by overwriting the content with the byte value above. In this case I want the 2 channel 350Mhz, which is GDS-3352 and byte 02:Code:echo -n -e \\x02 > /home/dso/bwconfFinally power the scope off and back on.Tested on an IDS-3152, firmware 1.29. YMMV, you may brick your scope, etc.

author: andrewkrot
author_rank: Newbie
timestamp: June 28, 2023, 12:44:44 pm
content: My oscilloscope did not have such a bwconf file. I had to create a file, after which the frequency change was successful.

author: s0nic0nslaught
author_rank: Newbie
timestamp: August 07, 2023, 06:25:14 pm
content: This seems to do something, but not quite as described.QuoteThis was tested on a physically marked GDS-3154. A value of 0x02 in the `/home/dso/bwconf` resulted in the unit to reporting a model of GDS-3354. I do not have access to a high frequency function generator to test the bandwidth effects of making this change though.It looks like `/home/dso/bwconf` only pertains to bandwidth and has nothing to do with channel count. It is simply an file with a byte value from 0x00 to 0x03 that sets model number and corresponding bandwidth (presumably).Firmware was v1.29 (seemingly the latest for the 350 MHz and below GDS-3000 variants). Telnet runs on port 23 as expected and login credentials are `root` with password `rd2423`.Either way good find. Hopefully this helps someone.

author: Wade2019
author_rank: Contributor
timestamp: November 25, 2023, 03:45:43 am
content: Has anyone tried the KG on the GDS-3000 family?I have an IDS-3154 with firmware v1.29 and had no luck trying to enable the bus feature.Any feedback would be very helpful!