General PLC HELP PLEASE!!

[plcnewb123]

Actually one very very last question!

Automation Direct is back ordered on the analog PLCs with the source analog outputs. Would sink outputs work? Ive been researching the concept of source and sink outputs and its been a concept personally tough to wrap my mind around in common terms..

Im sorry Im such newb with this all, it has been a learning process so far

 

[Albert LaFrance]

The terms "source" and "sink" refer to the digital outputs rather than analog. For your purposes, I think either will be fine - your initial design doesn't even use the digital outputs, and for instructional purposes you'll probably just be using some indicator lights, which will work with either type. It's just a difference in wiring.

Speaking of indicators, you might want to order a few, just to dress up the finished project!

Also, I forgot to mention that you'll need a battery to use the retentive memory feature of the Click. You may or may not need the feature, but you might want to have it available.

 

[plcnewb123]

Awesome, that makes sense, I will be using the analog outputs not the discrete outputs to vary the valve opening (in my case the meter)

and how would you tie in the indicator lights?

I am excited to order the hardware! here's what I am ordering today:

-MICRO ANLG PLC, 4 DC IN / 4 SINK OUT, 2-CH IN / 2-CH OUT, REQUIRES 24VDC PWR

-0.5AMP AC SYSTEM POWER SUPPLY LIMITED BY POWER BUDGET

-PROGRAMMING CABLE ASSEMBLY FOR EA1, STN MONOCHROME PANELS AND CLICK CPUS

-MEMORY BATTERY

-PACK OF RESISTORS FROM AMAZON

-SUGGESTED METER FROM EBAY


I hope that about covers it!

 

[Albert LaFrance]

Yes, I think that should do it. If you decide to add indicator lights, AD has industrial-style LED units (http://www.automationdirect.com/adc...22mm_Plastic/Plastic_Monoblock_Indicators/LED) that run on 24V DC, so you don't need external resistors. They draw 65ma, so your 500 ma Click power supply could run four of them plus the CPU.

Speaking of resistors, a good source for electronic parts is Mouser Electronics (http://www.mouser.com/).

As I mentioned, you might want to get a few variable resistors for your input and output voltage dividers, to compensate for tolerances of the fixed resistors and other circuit (and designer!) unknowns.

If you need switches (to select operating modes, for example), just about anything will work for learning purposes. For toggle switches, I usually use those wimpy 69 cent light switches from the home center (that's about all a 69 cent light switch is good for, IMO).

As far as the difference between sourcing and sinking outputs, the wiring diagrams on the respective Click CPU spec sheets show how the connections are made for each type. It's really just a question of polarity.