Rigol DS1054Z Unable to Trigger Cal-Signal at <= 0.6V - Page 1
Forum section: electronics / testgear

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 31, 2016, 09:44:30 am
content: can someone experience this? 10X probe connected to CAL signal (the 1KHz 3Vpp square wave that we use to compensate probe respond at far right bottom of the DSO). set trigger to lower than 600mV or 0.6V, and in my case BAM!, unlocked signal output goes all over the screen (as attached)

author: Tim F
author_rank: Regular Contributor
timestamp: January 31, 2016, 09:54:24 am
content: That's normal. You'll find that the trigger has some hysteresis, so you need to move it up a little if triggering on rising edge, or down a little on falling edge.

author: cs.dk
author_rank: Unknown
timestamp: January 31, 2016, 09:57:04 am
content: Mine does the same.. At 620 mV or lower, the waveform is just garbage. At 640 mV or higher it triggers normally.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: January 31, 2016, 10:31:02 am
content: Are your scopes unlocked to 100 MHz bw? I don't know if this makes any difference... but....Mine triggers just fine down to 260 mV, which is 13 steps up from the baseline. Each step is 20 mV. It loses the trigger at 240 mV.Of course it also depends on the Vertical Scale setting. At 500mV/div mine triggers stably down to 100 mV. Each step is now 10 mV.

author: cs.dk
author_rank: Unknown
timestamp: January 31, 2016, 10:41:34 am
content: Mine is unlocked.It seems, that the more zoomed in you are (Volts/div - don't know the correct term), the trigger gets better.I managed to trigger at ~140 mV

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 31, 2016, 11:49:38 am
content: Quote from: alsetalokin4017 on January 31, 2016, 10:31:02 ammine is "DSER upgraded". istr last time this bug occured but then later it dissappeared, triggering at low level was just fine, i dont know what i did to make this bug dissappear. this is not "everytime" bug, sometime it goes off.Quote from: Tim F on January 31, 2016, 09:54:24 amno this is not normal.. 0.6V is too large of hysterisis, my older DS1054E didnt have this kind of hysterisis. just imagine what hysterisis left to us to move up and down for a 0.5Vpp signal to trigger correctly? none. non-trigger at selected level of transition means miss capture and is no good, Type I Error: very heavy punishment... the DSO is unable to fullfill its core business, show the signal at the right moment..

author: nugglix
author_rank: Regular Contributor
timestamp: January 31, 2016, 12:36:59 pm
content: Quote from: cs.dk on January 31, 2016, 10:41:34 amThe datasheet does say that.Page 7 in the linked document."Trigger Sensitivity 1.0div (below 5mV or noise rejection is enabled)0.3div (above 5mV and noise rejection is disabled)"Document taken from:http://www.batronix.com/pdf/Rigol/Datasheet/MSO1000Z_DS1000Z_Datasheet_EN.pdfSo better try to reproduce their parameters and see if it holds to the specs - or not.Beware of the footnote...Cheers

author: sync
author_rank: Frequent Contributor
timestamp: January 31, 2016, 12:49:32 pm
content: Do you have trigger noise rejection on?My DS1074Z triggers at ~0.3div (~300mV in your case) and at ~0.6div (~600mV) with trigger noise rejection on.

author: onlooker
author_rank: Frequent Contributor
timestamp: January 31, 2016, 01:08:45 pm
content: It could be due to the trigger levrel calibration being off/drifted.A easy way to verify this is to show a trangle wave in near-full vertical scale. Now move the trigger level up and down and check whether the intersection point of the vertical "T" marker line and the horizontal "T" marker line are always on the waveform trace.

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 31, 2016, 01:28:28 pm
content: ok i shutted down the ds1z fw minutes ago. turned back on, now it can trigger at ~0.3V correctly. pressing the trigger menu, NoiseReject turned out to be at OFF state (remember this is after reboot). when i turn ON NoiseReject, it goes back to the OP problem, trigger only at > 0.6V weird, maybe some unseen noise going on? i have computer turned ON next to it.. trigger gets better at NoiseReject OFF.. but earlier when posting the capture above, i havent touch NoiseReject menu, so its weird... maybe the earlier boot, the NoiseReject is at ON position by some luck... and now the second reboot, the NoiseReject is at OFF, also by some luck, i dont know what was going on...

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 31, 2016, 01:38:57 pm
content: Quote from: onlooker on January 31, 2016, 01:08:45 pmdo i have to self-cal frequently? man this new generation X scope calibration is a pita half an hour or so, not like older ds1e which takes only minutes..

author: alsetalokin4017
author_rank: Super Contributor
timestamp: February 01, 2016, 01:14:22 am
content: I remember seeing in the manual that if the ambient temperature changes by more than a couple of degrees you should recalibrate. Takes 17-18 minutes on my scope. Scope should be warmed up for half an hour if you are doing quantitative work anyhow.