7/18/2014 7:36 PM | |
Posts: 7 Rating: (0) |
I think it is common ground. I'm not too experienced with these. So I'm providing VFG 24V now. and connecting R like 5.6Kohm. And connect FG signal input to PLC. I know PLC input has resistance like 6Kohm? what I also think if I can get VFG from PLC input side and directly use PLC input internal resistance as R for the attached fan motor requirenment it will be enough. That way I don't need towire a resisitor outside of PLC. so I want to hook SB orSMwhose M as 24V. I suppose that's called pull-down? I just want to find a SM with many HSCs. Or maybe connect several of them.I needat least 4HSCs to motinor.
AttachmentFan input.pdf (165 Downloads) |
Last edited by: szxz2003 at: 7/18/2014 8:25 PM |
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7/19/2014 10:32 AM | |
Posts: 5225 Rating: (1192) |
Hi there, The functioning of the HSC is for inputs on the CPU itself. I can not understand why you are not using the onboard inputs?.. some of those can handle up to 100kHz. I suggest you have a look at.. {LINK} Remember you have to avtivate the HSC function in hardware configuration. In the later S7-1200 V4 you can select any input for HSC function; Prior to V4.. you have to use what is reserved. The onboard inputs of the CPU can also be connected for NPN operation. Please have a look at this in the documentation that came with the PLC, or see this in the System Manual (..an essencial guide to have.) I hope these words are of help to you. w |