Multiple PLCs, one Touchscreen , Automation Direct

Hello, all. Am being brought in to complete an unfinished project. The application is to control a secondary operation on 9 separate machines, each using a standalone 205 with D2-240 CPU. The customer would like to control (basic on/off switches and count presets) from a central touchscreen. I have used the A-D stuff in the past, but never in a networked situation. I saw in the literature they offered multiple HMIs for single PLCs, but didn't notice information on the opposite situation.
The machines are physically located within 40 feet of each other (as the crow flys) in a U shaped arrangement, 40' being the longest spread (diagonal measurement.) The touchscreen would be located in the center area of the U.

Can this be done? What devices are needed?
Any help is certainly appreciated.

-tommy23t

I've never done it, but I don't see why you can't do it if you use RS-422 for communications. Assign each PLC a station number, then reference the station number with the tag. For example, to read V2000 in the PLC with station #3, enter 3-V2000.

Tom (Jenkins) has probably done this, so see if he chimes in here with some advice.

beerchug

-Eric

I've done the opposite, single SLC with several AD touchscreens. Allen Bradley had me looking at all kinds of AIC modules and whatnot to use panelviews. I called Automation direct's tech support (before buying anything) and they told me exactly what I had to do and e-mailed me a lot of useful information.

Sure this can be done. You have two options available to you.

RS-422 - The wiring will have to be in a daisy chain arrangement with the touchscreen as the master. Belden 8102 is recommended. The plc's will need a RS-232 to RS-422 convertor for each plc. The touchscreen will support RS-422 natively. Each plc will be assigned a station number and the touchscreen will access the station like so, x-V2000, with the x being the station number and V2000 being the memory address.

Ethernet - The wiring can be in any arrangement. Cat 5 is of course used. This will require a H2-ECOM for each plc and an EZ-Ethernet card for the touchscreen. The addressing is the same as above.

Personally for ease of wiring and troubleshooting I'd go with ethernet, but that's just my preference.

Sounds good, guys. Thanks for the responses. I have a good direction to go, should be a fun project.
-tommy23t

Wait a minute...

Sorry to be the bearer of bad news, Tommy...

The DL240 can't use RS-422. Both ports are RS-232 ONLY. You'll need to swap the DL240s for DL250s (or, better yet, the new DL260s) to use RS-422.

I don't know of any other solution.

beerchug

-Eric

On second thought...

Icky's ethernet idea may be another solution! If you have a spare slot on all the PLCs, you could stick an H2-ECOM module in there. Slightly cheaper than swapping CPUs, unless you can return/sell/etc. the DL240s to recoup the costs.

Another 'slot-based' solution would be a D2-DCM module to give you an RS-422 port.

I don't know if you can stick a F2-UNICON RS-232 to RS-422 adapter on each PLC and have the ability to network them...

beerchug

-Eric

(Yikes! I type way too slow.. crossed over your reply)

Thanks, Eric. I think the best way to go will be the way icky812 suggested, with ethernet. As he suggested and looking at their website, I would need the H2-ECOM for each base, the ethernet card for the touchscreen and an ethernet switch.
This will allow easier additions in the future. Who knows what they would need to monitor down the road? Feel like I'm way late to the party with networking plcs, just never had the opportunity.

You prolly haven't heard the last on this, fer sure.

Thanks again.

tommy23t

You think YOU type slow?...

I agree that ethernet would be the way to go (assuming there's a empty slot in each PLC!).

You're not the only one "way late in the party". We build stand-alone equipment (i.e one PLC per machine), so I haven't had much opportunity to delve into networking either...

beerchug

-Eric

P.S. Your list of items sounds right, but don't forget to include CABLES in that list!...

Re: Wait a minute...

Eric Nelson said:

Sorry to be the bearer of bad news, Tommy...

The DL240 can't use RS-422. Both ports are RS-232 ONLY. You'll need to swap the DL240s for DL250s (or, better yet, the new DL260s) to use RS-422.

I don't know of any other solution.

beerchug

-Eric

Click to expand...

Just got finished helping out an astronomer buddy extend the range of his connection to his scope (didn't want to sit out in the cold, go figure).

He's using RS232 to RS422 converters to change the signal to RS422.

Still waiting on the status report (not going to sit out in the cold either), should be a piece of cake.


John

RS-232 to RS-422 Converter on each DL-240 will work just fine. Check out Automation Direct Website to find this converter and compare the price of the converter with the price of an ethernet card in each plc.