thanswijk Posted January 16, 2019 Report Share Posted January 16, 2019 Hi, i'm trying to control a DC fan which needs a 25 kHz control signal. The control line is connected through the NPN output of an EX-D16A3-TO16 expansion module which is connected to a V1210. But one thing isn't clear to me at the moment: The expansion module can send a frequency of 1Hz - 32 kHz. So a MI should be enough for the job. But when I look in the help file under "Configuring a High-speed Output (PWM) > Frequency (F)", it says that the Software Units of a V1210 are 0.1Hz (500Hz = 5,000). This would mean that an MI would not be enough because a value of 32,000 would mean I only send a frequency of 3,200 Hz, instead of 32,000 Hz. I cannot select an other operand than a MI, so can I not use this expansion module for sending out an 25kHz signal to my fan? Quote Link to comment Share on other sites More sharing options...
MVP 2021 Flex727 Posted January 16, 2019 MVP 2021 Report Share Posted January 16, 2019 3 hours ago, thanswijk said: But when I look in the help file under "Configuring a High-speed Output (PWM) > Frequency (F)", it says that the Software Units of a V1210 are 0.1Hz (500Hz = 5,000). It says V120, not V1210 in that help entry you're referencing. I think the V120 is an older Vision model, not Enhanced Vision. Have you tried it to see if perhaps it outputs the PWM in units of 1 Hz instead of 0.1 Hz? @Cara Bereck Levy, does the Help file need to be updated for this function? Quote Link to comment Share on other sites More sharing options...
MVP 2021 Joe Tauser Posted January 16, 2019 MVP 2021 Report Share Posted January 16, 2019 11 minutes ago, Flex727 said: Have you tried it to see if perhaps it outputs the PWM in units of 1 Hz instead of 0.1 Hz? Empirical data is the best data. The spec sheet says the module will go to 32 kHz, so I would hook one up and put a scope on it to verify this. You can also send an email to support@unitronics.com to get clarification. Joe T. Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted January 16, 2019 MVP 2021 Report Share Posted January 16, 2019 I respectfully disagree with Flex, in that I think thanswijk's interpretation is correct with the software units 0.1Hz, so 500Hz = 5000. With a Range of 0.1 Hz to 100kHz. But as Joe says, the module's HSO frequency is 1-500Hz at PNP, and 1Hz - 32kHz on NPN. The one thing missing from all the info is how to drive it. In theory it won't drive with the innate 1210's higher unit. I tried a quick hardware config in Visi and it brings up an MI for the operand for the module's HSO frequency. This implies that the module is driven directly by an MI at 1Hz units, and I'd be going with this. When I am in doubt, I always do a test bench mockup (as Joe suggests) to find an actual result of something theoretical. cheers, Aus Quote Link to comment Share on other sites More sharing options...
DanT Posted January 17, 2019 Report Share Posted January 17, 2019 Hi; I got curious and hooked up a IO-D16A3-TO16 and tested the NPN PWM Output Frequency in MIxx ( I used MI10) set to 25,000 Hz. Duty cycle to 500 (50.0%) Scope shows a nice 40uS squarewave ( 25,000 Hz) 1.2K load on NPN Output bit of a curve on the rising edge, sharp on the falling edge, little bit of jitter Dan Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted January 18, 2019 MVP 2021 Report Share Posted January 18, 2019 Thanks for checking Dan. @Cara Bereck Levy Please include the use of the MI in the I/O manual. cheers, Aus Quote Link to comment Share on other sites More sharing options...
Cara Bereck Levy Posted January 22, 2019 Report Share Posted January 22, 2019 Hi guys! We don't deal with software configuration in the product sheets, only in the Help. The Help does show the frequency range/units, and does show that you need to link an MI. Hope this helps Quote Link to comment Share on other sites More sharing options...
DanT Posted January 22, 2019 Report Share Posted January 22, 2019 Hi Cara; You point out the PWM for Vision PLC's - PWM is On Board -- BUT ---- This point here is for a PWM in an I/O Module >> IO-D16A3-TO16 and this is done in 1 Hz increments ( as tested) also: >> EX-D16A3-TO16 also : >> EXF-RC15 An interesting note also about the PWM in the Expansion -- There is NO MB Trigger Bit Used If these are in HELP -- let us know where they are. Search by PWM does not show them Dan Quote Link to comment Share on other sites More sharing options...
MVP 2021 Ausman Posted January 22, 2019 MVP 2021 Report Share Posted January 22, 2019 Cara, adding to Dan's good explanation, your very first red outline is the crux of the issue. The modules do not use this rule, so there needs to be specific mention in their manuals of what you link them with. I could find nothing that says it is a MI. It is not a huge issue, but the information available is confusing. cheers, Aus Quote Link to comment Share on other sites More sharing options...
MVP 2021 Flex727 Posted January 22, 2019 MVP 2021 Report Share Posted January 22, 2019 I agree with Ausman - this is all very confusing. With the exception of the Standard Vision, V120, an MI will not hold a number large enough to drive the output to the maximum frequency in the spec. Quote Link to comment Share on other sites More sharing options...
vincentBsef Posted March 8, 2021 Report Share Posted March 8, 2021 On 1/22/2019 at 2:43 PM, DanT said: [...] An interesting note also about the PWM in the Expansion -- There is NO MB Trigger Bit Used [...] Dan Hello everyone. Sorry for digging up the topic. I'm just programming a PWM on an EX-D16A3-TO16 extension... and I actually don't see any activation bit. Should I consider that the activation is permanent, and that if I want an output at 0, I have to set the Duty Cycle to 0 ? I don't have the material on hand, I program for on-site intervention. I can't test immediately. Quote Link to comment Share on other sites More sharing options...
AlexUT Posted March 8, 2021 Report Share Posted March 8, 2021 Yes, Set Duty Cycle to 0 to have output OFF. B.R. Quote Link to comment Share on other sites More sharing options...
AlexUT Posted March 8, 2021 Report Share Posted March 8, 2021 Some additional information: All referred in help and in this post PWM frequencies are for on-board and snap-in modules, direct connected to PLC CPU. Expansion modules has 1 Hz step, and you have to follow IO module specification. B.R. Quote Link to comment Share on other sites More sharing options...
vincentBsef Posted March 8, 2021 Report Share Posted March 8, 2021 5 hours ago, AlexUT said: Some additional information: All referred in help and in this post PWM frequencies are for on-board and snap-in modules, direct connected to PLC CPYU. Expansion modules has 1 Hz step, and you have to follow IO module specification. B.R. Thank you for yout 2 answers. I did see this part in the messages above. But a reminder can't hurt Considering the changes I have to make to the existing program, I think I'll try to get the v350 I need. V.B. Quote Link to comment Share on other sites More sharing options...
vincentBsef Posted March 19, 2021 Report Share Posted March 19, 2021 (edited) Hello, I just started testing with this pwm output on a static relay. And I notice that with a duty cycle at 0, my output goes to a 1 logic : 24Vdc. I have to set a negative value to switch the output to 0. It's strange and unexpected. And not in accordance with the answer above. I wonder if I'm doing something wrong? Edit : I just noticed that the issue only occurs when the DC value goes directly from 1000 to 0. A passage by an intermediate value does not produce this pb. Therefore, I think it may be a bug ? Edited March 19, 2021 by vincentBsef Edit : New findings : Quote Link to comment Share on other sites More sharing options...
vincentBsef Posted March 25, 2021 Report Share Posted March 25, 2021 Hello. After taking a new ex-d16a3-to13 on another v350 on a test bench, I could not reproduce the issue. I then exchanged the 2 extensions and still can't reproduce this problem either on the bench or on the material in the machine. So I dont' get what happened. I'm pretty sure I didn't dream this, because I could repeat it on purpose....... But now, I invalidate my previous statement about this bug. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.