PLC model


Thread Starter


I am a newcomer of PLC. I am trying to design a control unit using PLC. It's very simple, just a few 24VDC inputs (15 inputs) and with corresponding LED output each. What model of PLC and peripheral devices should I choose? give me
the cheaper ones, if you know the price pls tell me.

Is it okay if I use it without any connections to the PC.. I mean, just the PLC supply, inputs and outputs.

This design is just for indicator purposes. I need anyone's response ASAP so pls. email me.... thanks!


Are you basically trying to use a PLC to turn some led's off and on? In regards to the "type" of PLC, that is generally to cheap part. The software to program it what can be expensive. Horner APG has some inexpensive PLC's and free
software (not sure if it will meet your density needs). You might also try PLCDirect for a "cheap" PLC.
I have worked with the Allen-Bradley MicroLogix line and it seems relatively cheap, compared to ControlLogix that is. You may want to look into them at ( "": ).
The MicroLogix 1000 may be too small for the number of outputs you want. The ML1200 may better fit your needs. The larger model's part number is 1762-L40BWA. My 1762-L24BWA (14 24VDC ins, 10 relay outs) cost me about $290.
Adding a memory module and real-time clock costs another $75 or so. A nice feature of the 1200 over the 1000 is that you can add additional I/O modules to the base unit.

I have only investigated these units. I have not used these in systems I have built for two reasons. They can not be programmed online. You can go online and watch the logic in action, but you have to change the program off line and
download the changes. They also do not do floating point numbers. Other than that, they are still pretty impressive.

I hope that helps,

Take a look at IDEC. They have a starter kit that includes a PLC, programming software, cable, and manual for $249. You might also consider Automation Direct whose low end PLC lists for under $100.

Micro-1 starter kit - Part number: ID mm-Micro1 - $249.00
1. Micro-1 PLC (FC1A-C1A1E)

2. Cable ($85 value)

3. WindLDR Windows based software ($249 value)

4. Training manual ($35 value)

5. Technical support (800 number)

Automation Direct,
Part: D0-05DD, 8 DC IN / 6 DC OUT MICRO PLC W/AC P/S - US$ 99.00

[email protected]
Look for some micro PLCs from IDEC, Omron(Japan) or if you are really want those real cheap ones, some Taiwan made I forgot the brand names.
If you are from RP, try Raon or just flip through the yellow pages you'll get a lot of good suppliers. But if your purpose for just to drive
some lights, check the cost and compare with using PC based control. Might be cheaper if you can assemble a light driver and find the
suitable software.

Rajan Dandegaonkar

Hi Jomer,

You can try B&R 2003 Series PLCs (Website: which are cheap yet much more
powerful than AB,GE,Simens and others. If you are unfamiliar with the Ladder Logic Programming you can use other High Level programming
languages such as C, Automation Basic (Similar to Basic language),SFC (Sequential Flow Chart) etc
for programming. I bet you will love
programming B&R PLCs. Negotiate with them you may
get programming Software Free !!
One more thing PLCs are meant to work stand alone.
You will need a PC only for developing the Application program and download it to a PLC.
After that PLCs are on their own.
Wish you a Luck !!

Rajan Dandegaonkar
Try PLCdirect. They are the cheapest. Do you know about ladder circuits or logic??? It will be as is easy as Boolean Logic.
I've used the IDEC Micro3's for a few small R&D applications and it's easy to program with their WINLDR software... ( You still need to do the
logic, which can always be soemwhat confusing) but these work very well.. Couple it with a little B&W LCD panel (Automation Direct, QuickPanel..) and no more buttons, readouts and switches.. all done with software....
makes life easy if you need to change something down the road.

Marc Landry

National Renewable Energy Labs (NREL)
Golden, CO