Ladder Control System Simulation with Mathcad 15 M10

The power of Mathcad in solving very complicated problems in various

engineering fields, is very well known. To the best of my knowledge,

industrial control simulation using ladder network of PLC's is not much

addressed and therfore, this worksheet will demonstrate the simulation

of a control system using Mathcad 15 M10 making use of the control

VBScript. One point worth mentioning is the Timer control which is very

important in various control systems. The control will be activated once

it is clicked and therfore, I have used the Timer in loop to create the

required time delay. I found that a loop of 10^6 will give very near 1 sec

and multiple of of this value i.e,say, 5*10^6 will give 5 sec. The motor is

connected direct on line (DOL) via contactor which have some (NC)

and (NO) contacts. On start up the worksheet the Start/Stop and the

Temp.LimitSwitch buttons should be activated first. The ladder diagram

is shown rung by rung.

Note: | | : Normally Open Contact.

|/| : Normally Closed Contact.

When activating both [Start/Stop] and [TempLimitSwitch] you will see

after 3 sec (which can be changed in VBScript), the changes in the

system.