motor sequencing - ladder logic required
motor sequencing - ladder logic required
(OP)
Im new to plc's and need some help on efficient motor sequence ladder logic:
Inputs(control) - motor 1
motor 2
motor 3
motor 4
Outputs - motor on 1
motor on 2
motor on 3
motor on 4
If only one motor is trying to start (one input high) then it should start instantly and then block the other motors from starting for a time period.
If two or more are trying to start together then one with higher priority should start instantly then the other(s) after the time delay and so on.
Can someone please provide the ladder logic for this design with description of operation.
Thankyou for any responses :)
Sean
Inputs(control) - motor 1
motor 2
motor 3
motor 4
Outputs - motor on 1
motor on 2
motor on 3
motor on 4
If only one motor is trying to start (one input high) then it should start instantly and then block the other motors from starting for a time period.
If two or more are trying to start together then one with higher priority should start instantly then the other(s) after the time delay and so on.
Can someone please provide the ladder logic for this design with description of operation.
Thankyou for any responses :)
Sean





RE: motor sequencing - ladder logic required
Check Phil's site out...it's pretty good for people new with ladder logic.
http://www.plcs.net/
Another great sight is http://www.control.com/index_html
Our website www.automationdirect.com has programming examples if you are using Koyo plc's. It's not really applicable if using other types.
Hope this helps some.
Carl
RE: motor sequencing - ladder logic required
From the posting, I assume that finally all the motors will get started sequentially after a prescribed time delay. Correct me If I am wrong.
Also how is the priority defined.
If it is a contact, priority can be ANDed with the Input to run one motor. Make such that when this motor starts, it initiates (starts)a time delay, say T1 for motor 1. If motor 2 is going to start, let that be T2. This TIMER T1 ON(RUN) contact can be used to disable the outputs of other motors 2,3,4.
again the priority contact / bit will enable the start of the next "suited" motor. Here another Timer T2, T3 T4 will start and will block the other pumps. A symbolic rep is given down:
(Sorry Lanky, I couldnot post the rungs. Your e-mail will be useful)
P1 is the priority Bit/ contact for Motor 1 (O/P 1)
If any other timers are running it will not allow the motor 1 to start.
If motor 1 got enabled thro this logic and starts, then T1_R in other logics
will be “1” and will not allow other pumps to run till 40 seconds delay
of T1, even if its priority bit is set.
Similarly for motor 2 (O/P 2)
I/P 2 P2 T1_R T3_R T4_R O/P 2
Everything can be put in AND ed logic.
K.G.Vijaya Kumar
RE: motor sequencing - ladder logic required
---||------||-------||---------------------------( )-
Input1 Input2 Input3 Output
Input1 & Input2 & Input3 = Output
Good Luck and keep us posted!
RE: motor sequencing - ladder logic required
Good luck!!
RE: motor sequencing - ladder logic required
RE: motor sequencing - ladder logic required
-| |- N.O.
-|/|- N.C.
-|^|- Trans On or One shot
-(S) Set
-(R) Reset
-(TMR) Timer
Start1 Hold stop1 Motor1
-----| |-----|/|-----|/|--------( )
|
|
Motor1 |
-----| |-----------
Motor1 Hold
-----|^|--------(S)
Start2 Hold stop2 Motor2
-----| |-----|/|-----|/|--------( )
|
|
Motor2 |
-----| |-----------
Motor2 Hold
-----|^|--------(S)
Start3 Hold stop3 Motor3
-----| |-----|/|-----|/|--------( )
|
|
Motor3 |
-----| |-----------
Motor3 Hold
-----|^|--------(S)
Start4 Hold stop4 Motor4
-----| |-----|/|-----|/|--------( )
|
|
Motor4 |
-----| |-----------
Motor4 Hold
-----|^|--------(S)
Hold
-----| |---------(TMR1)
TMR1 Hold
-----| |----------(R)
RE: motor sequencing - ladder logic required