On Monday 03 December 2018 21:03:05 Peter C. Wallace wrote: > On Mon, 3 Dec 2018, Gene Heskett wrote: > > Date: Mon, 3 Dec 2018 20:38:02 -0500 > > From: Gene Heskett <[email protected]> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <[email protected]> > > To: "Enhanced Machine Controller (EMC)" > > <[email protected]> Subject: [Emc-users] One more > > question, re powerup-powerdown glitches. > > > > Greetings to PCW. > > > > Is there a config for a field output that will not cause a glitch on > > pull low if power to the i/o board combo is switched? I have 3 > > circuits that are currently switched by sending a charge-pump to > > them, which I can still do, but I'm wondering if theres a > > configuration in terms polarity's that will not cause an ssr to be > > fired if its triggering led input, the - terminal, is direct > > connected, ot should I retain the use of the chare-pump and some > > home-made buckets, which give around a 200 millisecond lag to fire > > after the pump signal has begun to be sent. That lag is immaterial > > in comparison to the 3 second soft startup to start the spindles > > psu. The one thats critical is the hard on ssr firing, which has a 3 > > second timer so the machine on pumps the soft start bucket first and > > triggers a oneshot to enable the fully on ssr 3 seconds after the > > machine is enabled. That can't be rushed by powerup noise as it will > > trip a 20 amp breaker in the service. Any chance of that from > > powerup glitches and I'll have to continue using the buckets. > > > > Whats the verdict? > > > > Thanks Peter. > > > > -- > > Cheers, Gene Heskett > > -- > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > -Ed Howdershelt (Author) > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > The Field outputs are off at all times until the host commands them to > be on (the output pin is set true in HAL). > That is, they do not glitch on power up or power down. > > _HOWEVER_ They are solid state switching devices run by software so > you should never depend totally on the output state since a failed > device or software error could case the output to be "on"
So I'd better stick with the charge pump driven stuffs, thanks Peter. -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
