Asking for an inexpensive PLC recommendation

Is it not possible to find a combination of CompactLogix with 152 I/O for less than 7000 USD ?

This is what I proposed:

1 PLC CompactLogix 1679-L33ER
2 Power Supplies 1769-PB4
6 DI Modules 1769-IQ16
4 DO Modules 1769-OB16
1 End cap 1769-ECR
1 Expansion cable RTL 1mt 1769-CRL3

And yes, the price can be cut by using a smaller CPU (this one is oversized by far but is in "active" status) and maybe one smaller power supply
 
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I would look at still using a compact logix PLC since it is what you know. Pick the lower level processor - an L18 or so and use a remote I/O system with it - such as Murr elektronik Cube 20 system.

The Murr I/O is 1/2 the cost (or less) of the Allen Bradley I/O cards and works just as well (Better, IMO, since it is more flexible).

I'm guessing you could get the PLC for around $1.5k

(Take my below estimates with a grain of salt, it has been a few years since I've priced this stuff)

You need 6 16-input cards - but the Murr comes in 32, so 3 of those at around $200 a piece is about $600. 2 Digital output modules at $300 a piece is around another $600, plus the bus-node for another $300 or so.

Controller: 1.5k
Busnode: $300
Input cards $600
Output Cards $600
Outside power supply $300 (assuming ~ 20A 480/24VDC power supply)

About $3.3k give or take. Plus, you don't really have to learn any new software.

If you don't like the Murr, you can look into other IP20 remote I/O options: like the Weidmuller stuff (which I really like for inside panels). What makes Murr special is it all works on a single IP address, so you don't need an expensive controller to do a ton of I/O.
 
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I take it you haven't ever heard the phrase "You can find a better PLC than Allen Bradley but you sure can't find one more expensive"
I have a feeling that AB list prices are bloated, but that then gives room for significant discounts.

On a recent project, I was shown how AB 1734 I/O prices are comparable to Siemens ET200SP I/O, probably after discounts.
 
Now, I think that CoDeSys is a paid software, isn't it?. I have to take a look at it too.


It depends. You can buy the Wago version, called E!****pit, very powerful and works well with all modern Wago hardware, at a price. And then there is plain CoDeSys v3.5 which is free. Again very powerful software. You buy the required runtime for your PLC from 3S Software, which is about €50 per controller. If you only do one or two this works out very cheap. It is indeed a nice and flexible platform for high number of digital IO's.
 
what ever plc you choose, the most important issues to me are.

1. is there local distributors for spare parts if the plc, power supply, I/o goes bad.
2. where is the nearest distributor and how long will it take to get any spare parts.
3. if the machine goes down, how much downtime can they afford?
4. what are the maintenance guys familiar with?
5. do they have the software and laptop for the work?

the answers to these questions will guide you on your plc path.

james
 
I have a feeling that AB list prices are bloated, but that then gives room for significant discounts.

Have you ever noticed that when Boeing announces a jetliner sale, they use "list prices" that are double what the jets actually sell for ?

When the US abandoned the gold standard and the Bretton Woods international monetary exchange system in the "Nixon shock" of 1971, the executive order that froze prices to stabilize the economy had the side effect of prompting heavy industrial companies to create a list price x discount schedule system. It has stuck around in some industries, but most consumers don't see it because we don't buy locomotives or jetliners. Companies that entered the automation business after the 70's don't have that experience and history.

Anyhow, our friend Chantecler is in Venezuela, which knows a thing or two about price inflation. Opinions on price competitiveness and distributor policies in southwest Michigan is not necessarily going to translate to what he can get done in Caracas.

When you're building just one control system, in my opionion your first consideration should not be the purchase price of the hardware. When you have downtime pressure, skill and experience limitations, and availability considerations, you should place all of them above the purchase price consideration.
 
.....

When you're building just one control system, in my opionion your first consideration should not be the purchase price of the hardware. When you have downtime pressure, skill and experience limitations, and availability considerations, you should place all of them above the purchase price consideration.
Ding Ding Ding,

lo barato sale caro

i come from the DCS world originally and the price is an order of magnitude higher than even AB or Siemens PLC. There is good reason for some to go with that. Ease of programming being the top one. There's much more consideration than the initial hardware price.
 
I made a joke at the beginning of this thread but Here is an option from Eaton that programs in CoDeSys. US List price for this configuration is $2608.00

80 24V Digital Inputs
80 24V Digital Outputs

Eaton does not charge for their Branded CoDeSys software called XSOFT-CoDeSys

The whole shebang is 163.5mm Wide. This can be a good thing or a bad thing. But it's probably the smallest configuration out there.

As others said, there are a lot more considerations besides price but if you know CoDeSys and there is good support for Eaton where you are, then this could be an option for you.

** I made a mistake on the picture and it only shows 4 of the 16DO Modules but the list price and overall width I listed would be with 5 of the 16DO modules. Would take too much time to correct so I'm leaving the image as is. You get the idea. **

XC300.png
 
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what ever plc you choose, the most important issues to me are.

1. is there local distributors for spare parts if the plc, power supply, I/o goes bad.
2. where is the nearest distributor and how long will it take to get any spare parts.
3. if the machine goes down, how much downtime can they afford?
4. what are the maintenance guys familiar with?
5. do they have the software and laptop for the work?

the answers to these questions will guide you on your plc path.

james

I solidly agree with 1, 2 & 3. 4 & 5 don't come into it for us.
 
I would look at still using a compact logix PLC since it is what you know. Pick the lower level processor - an L18 or so and use a remote I/O system with it - such as Murr elektronik Cube 20 system.

The Murr I/O is 1/2 the cost (or less) of the Allen Bradley I/O cards and works just as well (Better, IMO, since it is more flexible).

I'm guessing you could get the PLC for around $1.5k

(Take my below estimates with a grain of salt, it has been a few years since I've priced this stuff)

You need 6 16-input cards - but the Murr comes in 32, so 3 of those at around $200 a piece is about $600. 2 Digital output modules at $300 a piece is around another $600, plus the bus-node for another $300 or so.

Controller: 1.5k
Busnode: $300
Input cards $600
Output Cards $600
Outside power supply $300 (assuming ~ 20A 480/24VDC power supply)

About $3.3k give or take. Plus, you don't really have to learn any new software.

If you don't like the Murr, you can look into other IP20 remote I/O options: like the Weidmuller stuff (which I really like for inside panels). What makes Murr special is it all works on a single IP address, so you don't need an expensive controller to do a ton of I/O.

I'm thinking of giving non-AB remote I/O a go for an upcoming CompactLogix job. Wago and Weidmuller look great hardware and price-wise. How well do they integrate into the Logix software? Unfortunately Wago can't track down an EDS file for their latest Ethernet/IP coupler (!) and Weidmuller's EDS file only seems to allow two modules to be fitted. I've come here hoping someone might have been through the integration process already...
 

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