Which PLC for 32 low voltage inputs and 32 240V AC outputs?

I have checked a few of the large manufacturers' web pages, but I have a hard time making up my mind about which model to choose. This is the reason why I'm posting this message, since I hope that you guys might be able to provide me with some valuable input.

What I need is a PLC can be wall mounted (no bare circuit board), preferably on a DIN rail. I need approximately 32 low voltage inputs, 32 output relays that can handle 240V AC and a few amps each, and four PWM-capable low voltage outputs.

What would be nice to have (not need to have) is the capability to have a distributed solution, so that all I/O does not necessarily need to be located at the same phycial location. Further, it would be nice if one could connect two PLCs of the same type, and let them share I/O.

The Siemens Logo! seems nice, and there are plenty of them available on eBay. However I got the impression that it does not have any PWM-capable outputs, and the analogue modules are quite expensive. I would appreciate alternative suggestions of which PLCs/PICs to use, preferably not too expensive.

Thanks!

There's manufacturer's list on this site,

http://www.plcs.net/chapters/links.htm

Well... it's question of money you want to invest, siemens is big company with great possibilites of their hw, but more expensive too. Anyway, every manufacturer is selling units for expanding main CPU and units on DIN rail.

There also 'operator panels' on market with built in binary/ analog i/o or even communication to external units.

I'm personally using siemens for stability and performance, they delivery support here is also great, for low cost solutions it's local manufacturer Tecomat, great stability and unit expansion too, and better software in many ways imho, but they don't have so many communication and other solutions like siemens have.

About the relays, units are always designed for 24V DC, so yo u simply connect another circuit with 24VDC->230VAC relays.

An OMRON CJ1 is din rail mounted and has I/O modules that will satisfy your Low volt and 240 Volt relay outs.

When you say PWM low voltage outputs are you needing relay switching of a PWM signal or an analog output in PWM?

Leadfoot, I need to generate signals between 0-10V, so I assume that I need a transistor output.

Regarding the CJ1, I had a quick look att Omrons web site, but to me it looks like the CJ1 has no PWM-outputs. However, there seems to be analog output modules available but I don't need the resolution of "real" analog outputs, and I guess that they are quite expensive.

I have browsed a few more manufacturers' web sites, and found out that most so called micro PLCs meet my requirements, except that none of them seem to have four PWM outputs. Since cost is a concern, and the micro PLCs seems cheaper than the fully modular ones, my question could probably be rephrased as follows:

Which micro PLCs or other "cheap" PLCs can handle at least four PWM outputs?

Hej,


I am not 100% sure but I think if you look at a GE FANUC MICRO with an expansion module you will probably find a quite inexpensive PLC for your needs.

I took a quick look and

IC200UDR064 64 Point PLC,(40) 24 VDC In, (24) Relay Out, 24 VDC Power Supply​

With 2*Analog output expansion:​

IC200UEX626 6 Channel Analog Combination, 4 Analog In, 2 Analog Out, 24 VDC Power Supply


​

It is not a PWM analog but configurable for 0-10V or 4-20mA.​

The Versapro software(ladder) is easy to use and quite inexpensive.​

Hej MrQ,

Thanks for your input! I was actually reading the GE VersaMax Micro PLCs and Nano PLCs manual when you wrote your reply. Instead of having analog expansion modules, one can use a 14 point micro PLC with transistor outputs, which has four PWM outputs, and get 240 VAC relay expansion modules. Unfortunately the maximum current the relays can handle is 2A.

Any other suggestions, someone?

You may want to checkout www.automationdirect.com

Just about anything you use will cost because of the number of I/O involved. I think I would consider the DL205 series and use analog outputs. Also consider using just plain DC outputs and use din rail mounted relays, this can offer 5, 10, 15 amp or more capabilities.

I think you will have a hard time to find a PLC with more than 2A 230V AC outputs. What are you going to use them for?

Maybe you should consider using 24V outputs and external relays.

Entertron worth considering!

thobjo said:

What I need is a PLC can be wall mounted (no bare circuit board), preferably on a DIN rail. I need approximately 32 low voltage inputs, 32 output relays that can handle 240V AC and a few amps each, and four PWM-capable low voltage outputs.

Click to expand...

No bare circuit board? Is this really a concern if the plc is mounted in an enclosure, like it should be?

Entertron has the Elite 2000, with the following available:

• Up to 64 inputs >>> 12-24vdc, 120 AC, 240 AC, 24 AC
  
• Up to 64 Outputs >> 120 AC, 240 AC, 24 AC, 12-24 DC, TTL 5vdc
  
• 2 amp Triac or Transistor Output (Inrush up to 10 amps)
  
• Individually Fused Outputs and MOV protection
• 32K Program Capacity
• 2 Serial Ports
• Operator Interface Capabilities
• Networking Capabilities
• Pluggable Terminal Blocks
• Up to 16 Analog I/O - 12 Bit (includes Thermocouple and RTD capabilities)
• Windows or DOS programming software
• 7 year warranty
  

Plus a lot more not mentioned

"Elite 2000 Link"

Sounds like everything you need in one easy package, with FREE programming software, FREE tech support, and a very good warranty. And the price ain't bad either!

regards.....casey

I agree....just use external relays and then you will have no worries about voltage and current.

Well... usage of external relays is common and i think cheaper then special unit too.

Anyway, how much do you need to control inputs and outputs really? Maybe you can use distributed modules as well, i used some Advantech modules before time and they was really cheap and quite easy to control (in my case it was PC panel with touchscreen connected with 9 x 8 analog TC units) with visualisation SW on PC or simple core PLC.

Those modules are simply connected via rs485 or ethernet and offer almost every possible i/o type.

try it here if you want :
http://www.advantech.com/eAutomation/ADAM/

and here's list of rs-485 binary line
http://www.advantech.com/products/Model.asp?Category_ID=1-UE79C&BU=&PD=ADAM

I think some of other companies may offer very similar solutions.

Thank you all for wasting your time on my thoughts, I appreciate it a lot!

There is a reason why I haven't told you about what I'm going to use the PLC for is that last time I mentioned that I'm going to use the PLC for building automation in a private home, the thread lost its focus completely. Now that you know that I'm going to use it for home automation, I ask you kindly not to suggest non-PLC-solutions such as IHC, EIB or X10, and since I do care about my family I'll let a certified electrician install the things at an appropriate location. So now you know what I'm going to use it for, MrQ. The PWM outputs will be used for controlling something that I don't know the english word for, but its that kind of device that controls the intensity of the lights.

CaseyK, the reason why I would prefer a solution that is not a bare circuit board is that it would be a lot nicer (good motivation, I know ) to have a PLC with its own plastic housing, even though it will probably be mounted in a "case". In the best of worlds I will get hold of a PLC wich can be mounted on a DIN rail in a standard DIN rail enclosure with the MCBs, RCCBs and possibly some extra relays.

So far I have found a few models that are of iterest to me. They are:
* GE VersaMax Micro PLCs with four PWM outputs, 2 A/relay.
* Hitachi Micro-EH PLCs with four PWM outputs, 2 A/relay.
* Crouzet Millenium II+ with six PWM outputs, 8 A/relay.

I thought I had found THE PLC when i saw the specifications for the Millenium II+...until I realised that one can only attach one I/O-module, and thus not get as many I/O as I need.

rsdoran, I didn't find any products from AutomationDirect with PWM outputs, and the analog expansion modules, with two outputs each, were almost as expensive as a Millenium II+ PLC.

MrQ and Rsbad454, yes I could use external relays, especially since 2A would probably be enough for most outputs (since we use 240 VAC "over here")---only a few of them need to be able to handle 5A.

Marius, yes distributed modules would definitly be a good soultion. Can I connect these modules to "any" micro PLC with and RS485-interface, or does it explicitly need to have support for distributed I/O using RS485?

Thanks!

thobjo said:

The PWM outputs will be used for controlling something that I don't know the english word for, but its that kind of device that controls the intensity of the lights.

Click to expand...

That's a dimmer. You can overcome lack of a PWM output for dimmer control by hanging 4 resistors from 4 relay outputs. Then provide a 4 bit binary signal to these outputs for 16 different dimmer settings. Way less expensive then PWM. Just as good for a dimmer.

Additionally I agree with you on a none-exposed, or encased PLC. Sometimes you never know where that screwdriver's gonna go.....

The AD DL 205 or maybe even a DL 06 should get you where you want to be.

BTW take a look at this site: www.controlanything.com