DOL Starter PLC Program

[Meyers Mills]

I have been using Dol for years but I need a practical guide on connecting NO Start /NC Stop .
Let's assume absolute address for Start in ladder program is
XO1 and Stop is XO2.
The X01 is tied in with coil or comes from NO Start PB? Please I want practical solution
Thanks

 

[parky]

Not quite sure what you mean but assuming a standard start/stop circuit in PLC logic then The top rung will be false until the start button is pressed, when pressed and assume the stop button is true (N/C contact) then the contactor Y0 will energise, this in turn is Ored around the Start button to "Latch" it in, Pressing the stop button breaks the rung turning off Y0.


Start X01 Stop X02 Contactor Y0
-----[ ]------+----[ ]-----------( )
|
Contactor Y0 |
-----[ ]------+

You can add other contacts like alarm to de-latch just like the stop button but N/C contact so alarm bit is energised then the latch drops out.
The above assumes the Stop button is N/C so true.

 

[drbitboy]

I find a good place to start for most problems is here:


http://www.contactandcoil.com/patterns-of-ladder-logic-programming/


Those design patterns are used over and over.


The [Start/Stop Circuit] pattern is what you seem to be looking for in this post, which is exactly what parky already provided as well.

 

[Meyers Mills]

Hi drbitboy, I want to learn how the start /stop push buttons are wired to the plc inputs. The output from the program will energize the motor contact.
How is Stop /Start /Overload at plc inputs?

 

[drbitboy]

• What PLC are you working with?
  • What kind of inputs does it have?
  • What kind of outputs does it have?
  • Can you find the reference manual for the PLC?
• What input switches are you working with?
• What is the motor contact that are you working with?

You should be able to find details about how to connect the inputs and outputs in a manual.


For example, find a page like this for your controller.