And how many pulses does the sensor deliver per revolution ?

Ella_68

Hello Chip_plc,

that will probably have a logo!not be implementable. If, as you write, one revolution emits one pulse, then you have a maximum of 3.5 pulses per second.

That would be too few pulses for precise speed measurement at lower speeds. Even if you do this with a time measurement between the pulseswould try, the tolerances of the cycle times and the rounding of the arithmetic building block of a logo would distort this result.

Due to the low number of pulses, you have an inaccuracy of 2.8571m (1 revolution) in the total length. Also there are no half impulses, so you move on to the next onemust go to an integer value (that would be 7 pulses = 20m). You can record this area using a counter that resets itself after 7 pulses. This reset pulse in turn triggers a counter that counts the 20m steps. However, due to the rounding of the arithmetic module, too few meters are always displayed.

Greetings Ella_68

(translated with Google)

LOGO have not a great calculation blocks, and are limited. So i must make some tricks.

LOGO have for calqulations a max only of integers to 32.767. Counters to 99.999

So i have make the programm for counting the length in 2 parts.

Part 1 calculates the meters until 1000 meter ( 1 kilometer)

Part 2 calculates the kilometers.

You must calqulate them by yourself!!

The programm counts max to 99.999 km, its long enough for you?

Also a part for calculating the RPM, it works very slow, every minute the value on the display is refresed. If its to slow for you then an onther programm is also possibility.

Counts the time between 2 pulses in seconds. Calculating 60 / pulses is also the rpm

Look....

Toerental1 has now a quicker working rpm, every 10 sec the value is actualiseerd.

Toerental2 works different, it messure the time between two pulses on the puls-input and calculaat the rpm. Thats the max.

Hello Chip_plc,

How accurate does the display have to be? Toeternietoe's program already has a difference of 1m after 3 pulses. My approach had an error of 1m per 100m (that's why I didn't publish it). This time calculate up to 100km. You have a lot of waste there.

A different approach to the speed: The system is determined based on the inertia of the amount of paper and the load on the power gridhave no direct control of the motor. In my experience, such drives are controlled via frequency converters. Depending on the type of frequency converter, you can either adjust the motor speed via the data interface or a parameterizable analog (0(4)-20mA) output. If this is available, you can use it as the basis for your logo.

Greetings Ella_68

(translated with Google)

Ella_68

Hello Chip_plc,

How accurate does the display have to be? Toeternietoe's program already has a difference of 1m after 3 pulses. My approach had an error of 1m per 100m (that's why I didn't publish it). This time calculate up to 100km. You have a lot of waste there.

 The programm is much better!!

3,5 puls is 10 meter, 1 puls = 2,85714.... meter. My programm works wit 2,866, a little mistake.

Only the display is in meters, so if there are 1000 pulses my programm dispay 2866 meters in stead of

2857 meters...

The display is rounded to hole meters. So with a littele pulses there is a roundingsdifference. Z.B 1 puls = 2,86 meter, but on the display show 3 meter

Hello Toeternietoe,

Your program shows how you can implement something like this with the Logo!. As I have already written, my approach was not much different. But just the small error adds up with a maximum length of up to 100km. The rounding in the display and the tolerance by 1 pulse per revolution do the rest. Therefore, the display would be an estimate rather than an actual recording.which in my opinion is absolutely useless in this case.

In my opinion, the logo is unsuitable for this task. More impulses and an S7 that has a higher counting range would be a much better choice.

Greetings Ella_68

(translated with Google)

Thank you all for the answers! I'll keep in mind S7 instead of Logo!

Meanwhile, without abandoning Logo, which I want to test for this job....the acceptable error should be 1-2%. Plus, the sistem must be stand alone/ independent from other devices.