S71200 HSC Slow to Respond to changes

Hello

I have configured a High Speed Counter on the S71200 PLC and it is counting the frequency of pulses. The response of the counter however seems quiet slow. ie when the speed of the pulse sensor changes the counter is slow to pick up the change. I have carried out a very simple configuration no HSC Ctrl block etc used. I have hear that HSC require an interrupt? is this true and if so how is this set on the HSC on the S71200

thanks

Check this out, page 80:

http://automatika.etf.bg.ac.rs/file...rija/1_Vezba/s71200_easy_book_en-US_en-US.pdf

It looks like the averaging to calculate the average velocity is getting in the way of the updates. This is the Alpha-Beta-Gamma filter should be used.

Have you checked what is the averaging time of your HSC inputs? This parameter is configurable in the software, and you should reduce this value, if you think the counter is slow.

I am familiar with S7200 PLCs, however, the concept is the same as far as high speed counters are concerned! the counter will count from zero up until the CV (Current value) reaches SV (Set Value) this is WHEN an interrupt routine (a subroutine that gets triggered immediately regardless of scan cycle) it interrupts the whole scan cycle and perform the logic contained in that interrupt routine. if you used a wizard to generate the HSC code, then surely there will be an interrupt routine generated as well.

if you are getting inaccuracies make sure you do not have noise and that you are using a proper cable...try to hire a PLC programmer or an electrical enginner to help you out.


hope this help.
Kyle Sleiman

He is using it in frequency mode, not counting some value.

Yes because i am using a frequency configuration on the counter there is no interrupt allowed. I thought that something would be required in order to reset the counter (even if it measuring frequency or counts) to verify each pulse by resetting the HSC after each input pulse has occured

Where can i check

"the averaging time of your HSC inputs"

I have not checked this? Thanks

Im going to be rude junior memeber now.

CANT YOU READ THE S7-1200 EASY BOOK?!!!?!?!?!?!!?!?!?!?!?!?!?!



























page 113.
You really need to start getting this "read a manual thing" and try to find yourself.

Easybook is not very helpful at all. I was referred to it many times. did you even see the section on how to configure a HSC, it is terrible, very limited info. Only for some advice and hours of playing around i would never have figured it out. A person would have to be very experienced on Siemens plcs before the easybook makes sense.

No, I looked at my crystalball (ofc I have looked at easybook also manual, then F1 at TIA portal is very helpful). Information finding is very basic thing to do.

What if you need to do a job with a beckhoff, abb, festo, omron, mitsubishi, or anything you are not experienced with. You are going to need someone tell all new things that you have not done to you?

Read, read, look at hsc config (did you even look all options in there?).

Wel I would certainly ask people who know what they are doing if i got a job, thats the most important part of learning i.e. people who know what they are doing showing others.

Even page 113 of easybook just contains tables of module specs, nothing to do with configuration, perfect example of the use of easy book.

the description in easy book of HSC config is literally as follows:

"The CPU allows you to configure up to 6 high-speed
counters. You edit the "Properties" of the CPU to
configure the parameters of each individual HSC.
Configure the parameters for the high-speed counters by
editing the "Properties" of the CPU.
After enabling the HSC, configure the other parameters,
such as counter function, initial values, reset options and
interrupt events.
After configuring the HSC, you use the CTRL_HSC
instruction in your user program to control the operation of
the HSC. "

someone who has no experience with the S7, think about it would they be able to configure a HSC

Here is my page 113.

Page 118 in newest easy book that is easily found with goolge keywords : "siemens support s7-1200 easy book"

Wel this is my page 113, this easy book i have that was given to me here is not useful, when everyone tells me to look at it, it is pointless




i dont think the image will upload, all that is on the page is a table of analog input specifications

here it is

Page 118 in newest(11/2011) easy book that is easily found with goolge keywords : "siemens support s7-1200 easy book"