Hello. 1
In this video we are going to learn DRVA or 2
DDRVA pulse command with this command. 3
The desired number of pulses at the desired frequency. 4
Really important to point desired number of pulses at the desired frequencies produced as another really 5
really biggest. 6
Important point is here absolute and ramped. 7
You need to take care of this word absolute command usage. 8
DRVA d100 D102 y0 y1 in here. 9
S1 I mean D100 is absolute pulse value s2 D102 pulse frequency 10
value is written to this register Y0 pulse output for Port Y1 is the y output selected is the 11
direction output port. 12
Not that the value written in S1 so in here D100 can be positive or negative. 13
This is really another important point. 14
For example if the current absolute value is thirteen thousand five hundred in the common usage if right. 15
If the right K20000 in D1 step or Saro motor or drive will drive will generate K6500 16
pulse in Y1 direction and it will go to absolute K20000 values. 17
So the difference between absolute and relative absolute we can say go five thousand five thousand. 18
This here if I say again go five thousand. 19
It never goes because it is a absolute position and it is still standing at 5000 and it know this. 20
So never goes to another point but if we say go 7000 it goes just two thousand more and it reach to 21
seven thousand. 22
If we say go 3000 position it goes to three thousand in here and it goes just four thousand as - 23
but relative we can say okay go to 1000 it goes to 1000 we can say again Okay go three thousand more. 24
It goes to 4000 because we said three thousand. 25
If we say okay go two thousand and it goes to six thousand two thousand more so relative and absolute. 26
This is the difference it is really different commands for the positioning. 27
So in here we can check wants to this application in the plc 28
The number of pulses for Channel 0 is kept in D1336 register number 29
of pulses for Channel 0 is kept in here. 30
That's okay. 31
So in here you can see and D1346 register whose value was k 0 32
before the DDRVA. 33
command was executed to execute DRVA comand the M0 must be on if the command is executed 34
a second time in the same way. 35
this command was executed it reached to 5600 after the 36
command was executed. 37
So because S1 is our absolute position so they will go from zero to five thousand six hundred is absolute 38
possible with the absolute possible. 39
That's okay if the command is executed a second the time in the same way there will be no movement in 40
the step or servo motor because the current pulse value is five thousand six hundred because it did 41
DRVA command will definitely wanted to go back to five thousand six hundred but there will be zero 42
pulses movement and the command is going to be and if the command is to be run again the value in S1 43
should be selected differently and when it is run the pulse will be produced to go to that value. 44
For example if if you are waiting at m 0 is activated that's okay and we we get our pulse output frequency 45
as 10000Hz or 10 kilohertz and we want to go to for example 10000-5600 46
and plc get 4400. 47
So the servo or stepper motor will go 10000 point with we will we will produce just 4400 pulses 48
to reach to 10000. 49
pulses point so these pulses can be defined as the point for example. 50
We want to go to 10000. 51
So we are staying or waiting at 5000. 52
So we are saying okay produce or absolute a pulse is 10000. 53
It will go to 10000 5000 produced pulse value. 54
So we cannot say okay we are waiting at 5000 and our next absolute possible is 10000. 55
We need to go to 15000. 56
That is not true. 57
So this is absolute. 58
And if we are moving as relative maybe you are right. 59
But for the absolute positioning for the absolute possibility. 60
We are just going to directly to that position. 61
We are waiting in here. 62
So if we ten times activate this contact on and off off and on On and off and off and on. 63
output y0 is never going to produce any pulse. 64
It will stay at five thousand six position always. 65
This is how DRVA command or DDRVA command works. 66
So I am finished for this video. 67
See you in the next video.