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No reading from high speed counter I/O address

Created by: szxz2003 at: 7/16/2014 11:02 PM (15 Replies)

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7/16/2014 11:02 PM	Rate (0)
szxz2003 Posts: 7 Rating: (0)	I was trying to get frequency reading from a fan frequency generator so I can get its speed. I am using CPU 1214C DC/DC/DC. I enabled HSC_5 whose 'I address' is 1016...1019.I configured 'type of count' as 'frequency' with 1.0s. And 'Hardware Inputs' is I1.0.I hooked up the Frequency generator input from fan to the PLC. And I called for ID1016 in programming but when the fan is running I'm getting '0' reading from ID1016. I also tried HSC_6 with I1.3 and ID1020. No reading either. I do compile and download by right clicking the PLC at the 'project tree'. Can anyone help? Thanks a lot.
szxz2003 Posts: 7 Rating: (0)	Last edited by: szxz2003 at: 7/16/2014 11:04 PM
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7/16/2014 11:06 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15556 Rating: (2467)	szxz2003 I was trying to get frequency reading from a fan frequency generator so I can get its speed. I am using CPU 1214C DC/DC/DC. I enabled HSC_5 whose 'I address' is 1016...1019.I configured 'type of count' as 'frequency' with 1.0s. And 'Hardware Inputs' is I1.0.I hooked up the Frequency generator input from fan to the PLC. And I called for ID1016 in programming but when the fan is running I'm getting '0' reading from ID1016. I also tried HSC_6 with I1.3 and ID1020. No reading either. I do compile and download by right clicking the PLC at the 'project tree'. Can anyone help? Thanks a lot. When you change the hardware by adding or configuring a HSC with frequency input, you also have to download the hardware configuration and restart the plc. Did you do that as well? Sadly, the download option does not clue you in that it would be a good thing to do.
	science guy
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7/16/2014 11:22 PM	Rate (0)
szxz2003 Posts: 7 Rating: (0)	Thanks for replying. Yes. I compiled and downloaded hardware and software again and restarted the PLC. Still no reading. Very odd to me. I haven't used HSC before but I've done and read quite a few material by now. I can't figure out what I'm missing.
szxz2003 Posts: 7 Rating: (0)
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7/16/2014 11:24 PM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15556 Rating: (2467)	szxz2003 Thanks for replying. Yes. I compiled and downloaded hardware and software again and restarted the PLC. Still no reading. Very odd to me. I haven't used HSC before but I've done and read quite a few material by now. I can't figure out what I'm missing. If you could, try moving your I0.0 and HSC5 signals and see if that works. It might be to get frequency to work properly it must be the first few inputs on the plc. You can check the s7-1200 system manual if that works to see why.
	science guy
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7/17/2014 12:16 AM	Rate (0)
szxz2003 Posts: 7 Rating: (0)	I switchedto HSC_1 with I1.0 and ID1000. When the fan is running ID1000 is still geting '0' reading.
szxz2003 Posts: 7 Rating: (0)
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7/17/2014 1:11 AM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15556 Rating: (2467)	szxz2003 I switchedto HSC_1 with I1.0 and ID1000. When the fan is running ID1000 is still geting '0' reading. HSC 1 should be wired to I0.0 not I1.0
	science guy
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7/17/2014 8:22 AM	Rate (0)
William_B Posts: 5225 Rating: (1198)	Hi Guys.. may I jump in? Which firmware version are you using for this project? It will help us if you could send us a copy of your program.. make a program where you only us the HSC. Please look at the topic [LINK]. Focus on the files left on 6/28/2014, 3:51 PM and 6/29/2014, 8:48 PM. Please understand the processes explained there before looking at 6/29/2014, 7:20 PM and the discussions following. Is it possible for you to toggle the input slowly at first to see if the counter value? Monitor the physical input on the watch table.. see if it goes on and off. Check again the counter value. Before connecting to a high speed signal.. please make sure that the input is set to the appropriate filter level. By default it is set to 6.3ms (?). You will see this setting under the PLC hardware configuration under the INPUT/OUTPUT configuration for the CPU. Please let us know it this helped. w
William_B Posts: 5225 Rating: (1198)
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7/18/2014 2:03 AM	Rate (0)
szxz2003 Posts: 7 Rating: (0)	Thank you. Turn out to be the frequency generator input from the fan needs to be pulled up to get above 15V. Now I can get the readings. Do you guys know if there's I/O module for CPU1214C that has HSC in it? I was thinking if I can just provide 24V at Mof extra I/O module without currently hanging resistors outside.
szxz2003 Posts: 7 Rating: (0)
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7/18/2014 2:17 AM	Rate (0)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/24/2025 Posts: 15556 Rating: (2467)	szxz2003 Thank you. Turn out to be the frequency generator input from the fan needs to be pulled up to get above 15V. Now I can get the readings. Do you guys know if there's I/O module for CPU1214C that has HSC in it? I was thinking if I can just provide 24V at Mof extra I/O module without currently hanging resistors outside. You will need to research the IM-151 remote I/O option and see what module suits your needs. Try configuring in portal to see if that works for you.
	science guy
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7/18/2014 8:05 AM	Rate (0)
William_B Posts: 5225 Rating: (1198)	szxz2003 Turn out to be the frequency generator input from the fan needs to be pulled up to get above 15V. Pull it up from where? Is it a common collector circuit? A digital input signal board could work. These can be wired for NPN. There is also one that can handle 5V @ 200kHz. w
William_B Posts: 5225 Rating: (1198)
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