Economical Remote I/O

We have an operator control station that is located remotely from our control panel. Right now we have 20 discrete wires running to the control station (without connectors) for the push button and light signals.

We are finding customers that don't know where they want to place the control station until our line is set up, so sometimes we need to rewire the station with longer cords.

Instead of making 20 pin connectors on cables that would need to be custom made on site by installers, I would like to look into using remote I/O.

I need to control 11 inputs and 3 outputs. I still need a hardwired connection for the E-Stop button.

We are using AutomationDirect 205 series processors, but their remote i/o is still pretty expensive.

I was wondering if anyone made a universal ethernet remote i/o system with modules at both ends where I could terminate the discrete i/o wires.

With this solution the installer would only have to wire the E-Stop hardwired circuit and make a Cat5 run with RJ-45 connector at both ends.

Maybe there is a better solution?

Thanks.

I like the Acromag EthernetIP remote IO. They make a version of Remote IO for Modbus 983en-4012, a 12 channel input/output card, $375.00
These are nice because they can be configured to have a watchdog timer to any state you want, and each channel can be an input or output. You've got to be careful and use npn inputs and pnp outputs. The only thing they could do better would be to make them a little easier to wire.

Thanks CroCrop. I would like to have AC I/O since that is what we stock for the majority of our machines.

I guess an alternative solution would be some kind of easy connection system so that our installers (whom are not electricians) can connect. The problem is that it needs to be easily configured for variable length runs.

By the way, the AutomationDirect ethernet remote i/o would cost $730 for 16 inputs and 8 outputs (ouch).

Take a look at Beckhoff IO as well.

http://www.beckhoff.com/

Discrete inputs are around $5.00 per point, analog around $100 per point - IO adaptors around $280. IP67 rated discret output blocks are $100 for an 8 point block.

They appear to have a really slick wiring system that distributes power through each module block - eliminating the need for other terminals for power/commons.

I've considered using it but I haven't yet used it myself. At least a few people on the forum think Beckhoff IO is OK stuff.

The product from Beckhoff is called Fieldbus Box and Expansion Box. You need one coupler module, which is a smart unit that links to the fieldbus and has a fiber-optic link for expansion modules, and however many expansions you need.

I've used the Beckhoff serial products, and love them. The ethernet model supports a couple protocols, including modbus TCP. Best, thanks to the IP-Link (a local fiber-optic ink between the fieldbus module and the expansion units) adding more modules is a snap.

Good Luck!

TM

Does Beckhoff support EthernetIP at this point?
Do they plan to?

How long would the cable run be? We find the cheapest & easiest for runs up to 50 metres is a simple long cable (with a connector at one end for non-electricians), and we provide some place to coil up the extra cable ("future flexibility", we tell them, "no charge for the extra cable").

Ethernet is usually used for networked and multi-branch applications, and/or where a PC or TCP/MODBUS-speaking-PLC is at one end, no?. Also consider RS485, very common for point-to-point remote i/o.

Have you seen the ADAM stand-alone remote i/o modules? I just noticed them in the B&B electronics catalog. I've never used these before, and it's not clear to me if they need a PC at the other end or if they talk to each other, but it's another option. Oh wait, those are dc...

Could you just use a small plc, maybe a DL06, and just rin a comm cable between them?

CroCop said:

Does Beckhoff support EthernetIP at this point?
Do they plan to?

Click to expand...

http://www.beckhoff.com/english/default.htm?busterm/bk9105.htm

However, it would be prudent to check with the nearest Beckhoff rep for availability: it is a known feature of some European companies to advertise a product not yet available for purchase.

All in all, very nice stuff. We have just started using Beckhoff remote I/O ourselves (albeit we are currently limited only to DeviceNet) - so far it has been a pleasure.

Thank you LadderLogic.

rsdoran said:

Could you just use a small plc, maybe a DL06, and just rin a comm cable between them?

Click to expand...

This would be a good solution, but if your remote is more then 50 ft away then you might need to run RS485.

Another possability is Dupline by Carlo Gravazzi. 2 or three wire com to the remote remote. The master plugs in to RS232 on the master PLC and it polls the remote.

Personally if the distance isnt very long, Id stick with the hardware. A short cable is still less expensive then the remote hardware.

If you're just dealing with pushbuttons and lights, how about using something like AD's OptiMate panels?

Look here

Thanks guys.

Hey rsdoran, the 250 processor in the main panel is already the master to 3 other dl-06 plc's on other machines using RS-485 and DirectNet so it would not be hard to add another 06 to the network. I would need to have a comm cable running to the operator station and another coming back out to the other plc's to satisfy the drop network spec.

It just seems weird adding a plc in the operator panel just for 11 in and 3 out although it seems to be the cheapest way.

The other option is like Fredderf said, make connections on either end of the discrete wire cable and make it extra long. The only two things I don't like about it are the wasted cable and the labor that goes into making the connectors ( 17 discrete wires).

I will take a closer look at Beckhoff and ADAM to see what they have to offer.

Hey burnerman, I thought about the optimate but I don't think it is very operator friendly and I am not sure about the long run. 60 to 100 feet.

Thanks again.

First time including an image, but here is what I was thinking (with more io of course).



This would be a more universal approach because you are not dependent on the plc manufacture's protocols. The downside is that you are not saving money on io cards.

As far as the plc input card is concerned it still thinks it is hard wired to the input device.

CroCop said:

Does Beckhoff support EthernetIP at this point?
Do they plan to?

Click to expand...

Crocop -

I checked w/ Beckhoff (I've been considering trying them out) and their rep told me that they have an Ethernet adaptor at the present but it does not play well with Ethernet/IP. An adaptor for Ethernet/IP has been developed and is supposed to be out in the next couple of months.