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.