Noob: Help with hardware - Countdown timer

Hello from Australia!

I'm in the midst of project for my work and I need a bit help.
Basically I'm building a timer for a HID (high intensity discharge) lamp thats rugged and idiot proof.

I figured a PLC would be the most cost effective and feature rich piece of gear I could get my hands on so thats why I'm here.
However I've not had much to do with PLC's before so I don't know where to start and what type of hardware I need.

The requirements I need for timer are:
Inputs:
- Start button
- Stop button
- Increment time up button
- Increment time down button

Outputs:
- 1 N/O relay contactor
- 1 N/O alarm output

Features:
- Display that shows the countdown time (display needs to be simple and clutter free.)
- Start button to initiate countdown.
- Stop button to stop count and revert counter back to zero time and lockout start button(see below).
- Increment time up and down in 10min blocks using up and down buttons, both before starting and during the countdown.
- Alarm output chime at 1min or 30secs before impending shutdown to notify user, maybe have associated flashing time display.
- 15min cooldown lockout, i.e the N/O relay cannot be closed for 15mins once the timer has timed out, this is to allow the lamp to cooldown before refiring (refiring a hot lamp will destroy them very quickly!)

To make it idiot proof the PLC will be housed in a box with the PLC control buttons hidden and just the screen and 4 buttons showing.

Budget: Ideally I don't want to spend more than about $150-180USD on the PLC.

Thanks for looking.
Hope someone can help.

I don't think you need a full blown plc, a "smart" relay should do the job.
There are many brands on the market, and several of them have free software as well. Do a web search for smart relay or programmable relay and follow the hits. Many smart relays also have simple displays built in, so you can save that cost as well.

Have a talk to Omron about the Zen, NHP about the Mitsubishi Alpha (they have some on special at the moment - clearance) and Schneider about the Zelio. They are all readily available in Brisbane and may do the job.

I know NOTHING about smart relays. But I was just thinking of a potential pitfall if Mercury Arc goes this route:
Are you sure that the timer values can be set during runtime ? It could be one of the places where the smart relay lacks some features.
Just to be sure that we (you) dont lead him down the right track.

I don't know about all the smart relays, but I've been using this one lately:
http://www.factorymation.com/s.nl/sc.2/category.22/.f

and the timer values can be changed at any time, even while the timer is timing.

Thank you all for the replies.

I've been looking at all of the suggested products carefully and so far the Omron ZEN seems to be the best fit for my application. The Price is AUD$170 which is in the ballpark.
The ZENS seem very easy to program and the manuals very comprehensive, exactly what I need for a first timer!

Thanks again.

exactly what I need for a first timer!

Click to expand...

No pun intended?