Interface

How would i go about interfacing an alarm either analogue / digital to a plc system.

Also how would i interface a motor to a plc.

How would i go about interfacing an alarm either analogue or digital to a plc system.

Click to expand...

Through an HMI.

Also how would i interface a motor to a plc.

Click to expand...

Through a Motor Starter or Drive.
A more specific question will stimulate a more specific answer.

What do you mean by Alarm? A NO/NC Contact from a thermal overload ? An Analogue Signal from a current transducer ?

You can interface the motor controls (ie thermal overload, MCB or MPCB and contactor or soft start or invertor) to a plc but you cant actually interface the motor direct to a plc (normally!)

What do you mean by this ?

Please clarify ?

504bloke said:

What do you mean by Alarm? A NO/NC Contact from a thermal overload ? An Analogue Signal from a current transducer ?

You can interface the motor controls (ie thermal overload, MCB or MPCB and contactor or soft start or invertor) to a plc but you cant actually interface the motor direct to a plc (normally!)

What do you mean by this ?

Please clarify ?

Click to expand...

A visual alarm, also a contactor on the motor.

For a visual alarm take one of the plc outputs and make a red beacon light up

For the contactor to control the on/off of this from the plc then wire the contactor from the plc outplut. Or if you want to know if the contactor is on/off then wire an auxilliary from the contactor to a plc input.

Thank you for your help.

Your welcome.

What exactly is it you are trying to do ?

Homework ? Extra Learning ?

Which PLC ?

504bloke said:

Your welcome.

What exactly is it you are trying to do ?

Homework ? Extra Learning ?

Which PLC ?

Click to expand...

You could call extra learning, i have to justify a plc to a company the plc in question is a directlogic 405.

Also how would i interface a motor to a plc.[/QUOTE]

Hello Dave 1971,

The first thing that you are going to do is to know the voltage rating of your contactor coil to switch on your motor, then you match this voltage rating to the voltage rating of the output of your PLC. If the output of your PLC is D.C. and your contactor is A.C then you must use a D.C. relay to switch ON your AC contactor.

As to the how to connect this relay or contactor coil, just refer to the manual of the plc you are using. Don't forget to protect you PLC output since you are loading it with an inductive load. I think the instruction is also included in the manual on how to protect your PLC output.

I hope this will help you.

set-csg

you can use annunciator windows to display alarms