Cheapest DH+ AB PLC

[mutabi]

Hey guys,

I have about 10 machines that have no PLCs installed. However we are wanting to hook them up to a DH+ network. All we will want to do, is turn on a few outputs which will turn on some relays. We are not wanting to actually run the machine with whatever we choose.

We could do remote IO but if the master is shut off, then we have no communication with these 10 machines.

Anyone know of a cheap/nifty solution?

 

[JesperMP]

I am curious. WHY must it be DH+ ?

 

[mutabi]

Because our current network is DH+ mainly and so we have blue hose ran to other machines close by. I figured it would be the cheapest way to add the machines to the network. The network itself is a hybrid DH+/Ethernet. I just don't have any Ethernet cable option close by.

I am however open to hearing alternatives that I may not be aware of.

 

[JesperMP]

Even if you dont have ethernet cable already, I suggest you go for ethernet.
The PLC will be much cheaper, better and futureproof.
The money saved can be used on ethernet infrastructure.

edit: Without any further description of your requirements, it sounds as if even an ML1100 could do the job easily.

 

[geniusintraining]

Even if you dont have ethernet cable already, I suggest you go for ethernet.
The PLC will be much cheaper, better and futureproof.
The money saved can be used on ethernet infrastructure.

You can also take your DH+ and put it on the Ethernet network and see all your networks... in the original post you are adding 10 machines (guessing) a few more nodes (PC's, HMI's) this is pushing the DH+ limits and you will have very slow connections once you put them all on the same DH+... Ethernet is much better option

 

[Geospark]

I'd whole heartedly agree that adding more nodes, to the order of 10, on to a possibly already large DH+ network, could slow it down considerably. I've recently replaced 5 of 12 SLC5/04's on DH+ with SLC5/05's on Ethernet and the difference in speed is substantial. I'll replace the rest in time.

You could hang a DH+ to Ethernet gateway on the existing network and cable for Ethernet around the 10 machines. A MicroLogix 1100, or 1400 with embedded Ethernet would most certainly do you then.

Here's one popular brand of gateway. You use it in Bridge Mode to enable communications between Ethernet/IP and DH+...

EtherNet/IP to Allen Bradley DH+ Gateway

George

 

[mutabi]

We already are using DHRIO gateways and I love them. The problem however with Ethernet is these 10 machines are spread out in the plant. Running Ethernet to them is possible, but will cost some $. I see the DH+ route as cheap and easy.

Unfortunately, it looks like there is no cheap DH+ PLC out there so I will have to start looking at the feasibility of using Ethernet.

Thanks for the responses guys.

 

[Geospark]

Just be aware...

If you do start looking at cabling for Ethernet, and these machines are a good distance apart, remember the 100 metre limit on Ethernet cable segment. If the distances are substantial enough, you might have to look at using fiber, adding another cost consideration.

Looking back at the DH+ option...

...Unfortunately, it looks like there is no cheap DH+ PLC out there...

I suppose it depends on what you'd class as cheap?

The SLC5/05's I used to replace the 5/04's were 2nd hand refurbished controllers that one of our AB vendors sourced from a global repository. We did a part exchange for the 5/04's to get a 7.5% discount on the cost of the 5/05's. This was a controller swap only, no chassis or I/O. You could try get a quote on 2nd hand 5/04's with chassis and output module for your relays. The 5/04's support DH+ natively, so you can terminate your blue hose cables directly at the controllers.

I don't mean to back track on what we've advised, Ethernet would still be the better option, but it's always good to have a plan B.

George.