Hello. 1
In this video we are going to learn cycle scan time. 2
This is really important for the plcs scan time and it is affecting outputs and inputs than readings 3
and the writings if scan tme value very short time or a little bit longer. 4
How can we know what is our plc scan time and where can we read it. 5
So let's take a look and let's do a little bit example and practice about it. 6
I will create a new project and I will give a scantime name and ss2 will be. 7
our cpu and I am saying okay. 8
New project is created. 9
Then come here then programs and scantime will be pou name and I will say okay we were connected to a 10
simulator and it still DVP simulator is selected. 11
I will stop our simulator and I will use serial communication to my real plc , see existing one plc 12
and in here tools and communication settings. 13
I will select serial communication also. 14
Before we start to check scan time and then I will go online to my plc. 15
But this is an empty project. 16
So let's check first. 17
Empty project. 18
Scan time. I'm transferring this empty project to my plc , it is transferring now and do you 19
want to go back to running state. 20
Say yes now we are at the run situation in here. 21
You can see our scan time is 0,1 - 0,2 ms so this is our scan time. 22
So plc is reading inputs then writing output and the complete project is in one loop. 23
It is turning back to end and to start position and end position is completed 0,2 milliseconds. 24
It is finishing so let's go offline and let's do write a little bit program LD M0 and let's say 25
out y0 and in here for example ld m1 and out y2 and in here for example LD M1000 26
timer T0 and 50 and in here for example LD M11 and in here counter as one thousand, 27
this is just a unimportant project just to check once to our cycle time and I will 28
send these things to this project to my plc and now it's transferring and I will say to yes okay remember 29
our scan time was between 0.1 millisecond and 0.2 milliseconds. 30
Now let's take a look once what we have is it changed or not. 31
So in here we are at the run situation. 32
Our scan time is still 0.2 milliseconds but 0.1 and 0.2 milliseconds. 33
And these programs is not affected to our scan time but what effects to our scan time. 34
If we write a lot of codes in here. 35
If we put for example 1000 or 2000 lines or 5000 lines or if we are reading analog inputs and if writing 36
analog outputs. 37
Or if we are working with the load cell modules and encoders and with the pulses and etc. 38
This scan time can increase a little bit more. 39
And this is really important to us . 40
If we are lose if we are working with very sensitive applications like an encoder like a cutting and 41
stopping of the materials and etc. this is really important. 42
And you can check your scan time in here than you can give a decision according to this time of your 43
about your projects. 44
So I am finished for this video. 45
See you in the next video.