PLC lader timers and counter in S7 300

[usman]

Hello friends I start newly plc programing with S7 300 but I dont know how to set and S_CU up counter, can any one help me about that with all settings.

Thanks and regards
USMAN

 

[ivo.maenen]

Selecting the counter an pressing F1 will always give you some kind of help.

If you choose a CU-counter you have the option of a 'box':

on the top you"ll need to write the adres of the counter; exaple C0

on the left you'll have the input's:

CU: count-up signal example; I0.0
S: set signal; the counter will go to a presetvalue
PV: counter presetvalue example: C#5

R: reset, making the counter zero

on the right you'll have the output's:

Q: '0' if the countervalue is zero, '1' if the countervalue is not equal to zero

CV: countervalue as integer

CV_BCD: countervalue as BCD

 

[usman]

Yeah the all I do same like that but its not stop on the same value many time I try it set same counter its count also but not stop on the CV velue. If you can give total advice to me.
Thanks and regards
Usman

 

[ivo.maenen]

The CV is only a preset-value. The counter will start again with this value instead of a previous value. Nothing more, nothing less.

Personally I like a CD-counter with the preset-value the value I want to count to. Then I will count down; example 5,4,3,2,1,0

I will will use the counter like this:


start C1 motor
-| |--| |--( )

Motor will be '1' if 'start' and C1 are '1'. C1 is '1' if it is still counting to zero.

When C1 = '0' , I will need to set the counter again to it's presetvalue at least if you want to start the motor again.

When you will use a CU-counter you will need to make a comparison if the countervalue is equal to a certain value on wich you want to make an action or stop an action.

 

[usman]

Thanks you friend I am very glad to meet good friends like you.