FeelTech FY3224S 24MHz Function Signal Generator: Manual Trigger has bugs - Page 1
Forum section: electronics / testgear

author: mcmusic
author_rank: Contributor
timestamp: January 28, 2017, 09:16:44 pm
content: Hi everyone,I have been playing around with my FY3224S in the Manual Trigger mode. My model seems to have some bugs here. I have attached some pictures showing the trouble.At first I selected a sine wave of 1kHz. Then I pressed the “count” button three times to enter the Manual Trigger mode. In line 1 of the display I selected a count of 8 waveforms and pressed the button. 8 waveforms come out well on CH1. With 9 or 10 waveforms, the 2 latest waves come out wrong. From 11 onwards the output is ok. See pics A - D.If I selected a square wave of 1 kHz instead of the sine, the 9th pulse is distorted (note the glitch to GND and an apparent longer “ON” time from 8-9 ms). See pic E.If you select a slightly lower frequency, for example 0.995 kHz, the output shows a similar behaviour as with 1kHz plus an additional signal jump at 10.8 ms. See pics F - G.At one time, the display got confused, showing “Manual Tri SINE”, but I forgot the exact button sequence to get this display. See pic H.Can someone check these findings with his FY3224S? Do you get similar results?Greetings,mcmusic

author: mcmusic
author_rank: Contributor
timestamp: January 29, 2017, 05:35:34 pm
content: Just a small Follow-up: The bug described above also appears in "CH2 Trigger" mode.My adjustments for the attached pic J:Ch2: 50 Hz, 1V Square.Ch1: 1 kHz, 4V Sine.With 5 presses on the Count button you reach the "Channel 2 Trigger" mode.Line 1 shows CP_COUNT=10 (adjust the number to 10).That means that every 20ms = 1/50Hz 10 Sine waves should be generated on CH1. Pic J shows that the very first burst is faulty, by the same reason from the previous post. The subsequent 15 bursts (and probably all thereafter) are as desired.Hint: If you want to produce the same thing, adjust CH2 and CH1 as described. Then press the Count button 4 times, then you will have "Ext Trigger" in line 2 of the display. Then set your scope to trigger mode "Single" - it will wait for a trigger signal. Then press the Count button 1 more time and enter "CH2 TRIGGER MODE". My newly arrived Rigol Scope caught pic J after that.BTW, the FY3224S has Firmware Rev. 2.0 2010-2014.Greetingsmcmusic

author: pascal_sweden
author_rank: Super Contributor
timestamp: January 30, 2017, 10:33:09 am
content: Just out of interest, what oscilloscope are you using in the first set of screenshots? Very nice display!

author: mcmusic
author_rank: Contributor
timestamp: January 30, 2017, 12:18:16 pm
content: Hi pascal-sweden,it is a very nice but bulky Philips PM3320A. But it is starting to develop faults. It now has a severe low pass characteristic on Channel 2 for >= 5V/Div (below it works ok). This did cost me many hours wasted debugging time in another project. So far I did not dare to attempt the repair of this PCB-cramped cabinet. Maybe it is only an electrolytic capacitor that went bad?I took the screenshots with my Canon S100 directly from the screen of the PM3320A.Greetings,mcmusic

author: Lighthammer
author_rank: Newbie
timestamp: June 06, 2017, 08:19:41 am
content: Got mine FY3224S 24MHz with Firmware 4.0No issues with manual trigger.