alarm annunciator project

[projectthief]

Hey Guys
I am a 42 year old studiying to be an electrician
The project reads as follows

" The project provides for a 15 input alarm annunciator system. The system has a common flasher unit, an alarm accept, alarm acknowledge, alarm reset push buttons.
Each of the 15 alarms are either initiated by a fleeting fault or long time connected fault. when such a fault occors then an audible alarm is raised and that particular alarm point light flashes at a fast pace. once the accept button is pressed then the audible alarm stops but the flashing light should continue flashing till acknowledge. Once acknowledged if the fault condition persists the flashing light changes to a steady light. once fault is cleared the light flashes but more slowly. now if the reset button is pressed then the light switches off.
this project envisages the use of push buttons, LED's Loud speakers etc apart from the ladder logic"

Can any of you folks tell me the hardware I will need compatible with schneider-electric (telemecanique) PLC. and how to cut my teeth on ladder logic in a short time?

Yours truly
project thief

 

[Analog]

Wow,

That's a tall order. Sounds like the old panalarm units I worked on. I suggest you lookup some tutorials on ladder logic, but around here, that would be solved using a microcontroller.

 

[Leftyretro]

Hi PT;

Well the hardware requirements are pretty straight forward, just count all the digital inputs you need to simulate field alarm contacts and panel switches. Count all the digital outputs needed to simulate alarm panel lamps, horn, etc. Just about any programmable micro, PLC, etc can perform the logic actions, it's not a demanding application.

Below is a link to a PDF document that defines industry standard terms used to specify how alarm panels can be set-up. Your task will be figure out which apply to your assignment and then turning these definitions into programming code so as to implement them.

https://www.electro-tech-online.com/custompdfs/2007/04/appk.pdf

Good luck
Lefty

 

[projectthief]

Annunciator project

Thanks for the reply Analog and Lefty,

I downloaded a few tutorials on ladder logic and practiced.
I still donot understand 'digital inputs' . Could I request you give the piecemeal hardware ( input and output) needed for example a 'temperature alarm' system.

be much obliged

PT

 

[Leftyretro]

Thanks for the reply Analog and Lefty,

I downloaded a few tutorials on ladder logic and practiced.
I still donot understand 'digital inputs' . Could I request you give the piecemeal hardware ( input and output) needed for example a 'temperature alarm' system.

be much obliged

PT

Well controllers, micros, computer, logic circuits, etc, 'talk' to the real world through their input and output capability.

Digital Inputs:

When we say a digital input we mean a signal read by logic circuits that can only be only in either of two states, on or off, 1 or 0, open contact or closed contact, just like a lamp switch except instead of turning on a lamp it's signalling the logic through the change of state. An analog input is an input where the logic can actually measure the magnitude of and make decisions based on that magnitude under prorgram control, kind of like a gas pedel controls the speed of a vehicle,

Some inputs may seem to be analog but are actually digital, like the thermostate control for your furnance. While it might have a dial where you set the desired 'setpoint' the action created is a contact open or closed depending if the ambient temp. is above or below the setting. That could be considered a digital temprature alarm input because it turns on or off the heat based on actual Vs desired temp.

Some digital inputs are special purpose inputs designed to follow a very fast on/off signal that's sending a code representing characters or numbers or both, this might be called a serial input channel, but it's really just a digital on/off input.

Your assignment defines an alarm panel that 'reads' field contacts to decide if there is an alarm condition for that specific input channel, so a simple digital input would be needed for each field alarm switch. You will also need local pushbutton digital inputs to perform the alarm acknowlegment and reset and other user switch functions your assignment requires

Digital outputs:

If the logic, controller, plc, micro, computer, etc is to make an external action happen at a specifc time or condition it needs to have output circuits. A digital output can be a voltage the goes from one of two states, say 0 volts or 5 volts, or control a electromechanical relay so that a contact can be controlled to be open or closed. In you applications you need to be able to light lamps on and off and turn a horn on and off, so you will utilize digial ouput circuits to perform those functions. There are analog outputs where the controller can place any specific voltage or current level within it's range, say 0-10vdc but this capablility is not required in your assignment.

So does that explain inputs and outputs well enough?

Lefty

 

[hatem_sniper]

thanks very much