3 PLC's on a wireless router?

[terrman 0]

I do this programing with one PLC. Is it possible with three PLC'S I have three plc's (AB 5000) which have ethernet cards. from PLC 1 ethernet card to PLC2 cabinet, i have cat5 cable run into a hub. PLC2 ethernet card cable into hub. From hub i have cat5 cable run to PLC3, which terminates into a linksys wireless router. PLC3 ethernet card cable to wireless router. Each PLC has a diffrent IP address eg. PLC 1......192.168.66.61 PLC 2.......192.168.67.61 PLC 3.......192.168.68.61 subnet mask 255.255.255.0 Is it possible to program from my laptop? Do i have to give the router an IP address similar to the PLC'S? the wireless feature is great to watch the machine and make timing changes while running Thanks for your help.

[BobLfoot 301]

What you describe is quite possible. Try the following setup: PLC 1 IP 192.168.61.66 Subnet 255.255.255.0 Gateway 192.168.61.1 PLC 2 IP 192.168.61.67 Subnet 255.255.255.0 Gateway 192.168.61.1 PLC 3 IP 192.168.61.68 Subnet 255.255.255.0 Gateway 192.168.61.1 Wired Side of Linksys Router IP 192.168.61.1 Wireless Side of Linksys Router Set for DHCP or any subnet set which your laptop is operating on. I'd recommend you plug your laptop into a wired port or the router and use the following settngs for a first test. IP 192.168.61.65 Subnet 255.255.255.0 Gateway 192.168.61.1 If you could specify the model of Linksys Router I could give a more specific answer.

[terrman 0]

Thanks for the reply. I have to use 61 as the last oct. I will try your idea, just switch the octals around and change the subnet mask. I am using a Linksys WRTg wireless router, and really need the wireless feature for programing.

[panic mode 246]

in that case you must change mask to 255.255.0.0 read more here http://forums.mrplc.com/index.php?showtopi...amp;#entry39324

[DanW 41]

I'm confused on the wiring. - PLC 1 and PLC 2 are wired to a hub (OK) - PLC 3 is wired to the hub (OK) "which then terminates into wireless router" (?) Does "terminates into wireless router" mean that the hub connects to the wireless router through a CAT 5 cable ? "PLC3 ethernet card to wireless router" means what? Are there 2 RJ45 ports on PLC3? Is the 2nd port a "switch" port? Dan

[BobLfoot 301]

OK I'll bite, with addresses like 192.168.66.61 , 192.168.67.61, 198.168.68.61 you'll need a 255.255.0.0 subnet mask. This addressing scheme defies normal IP layout. What is the reasoning?

[Contr_Conn 4]

Just wondering where this is coming from? Apparently from somone who can assign numbers without basic network understanding. Unless you change your mind, subnet must be 255.255.0.0

[hipoint2 0]

If you are going to use this router alot and have not bought it yet I would recommend one for a little more money. I also use this router for doing some programming and I have to have the panel door open for the router to get any type of signal and it kicks me off every once in awhile and the signal stregth changes all the time and I am only about 30 ft. away from the darn thing. Just my .02.

[TimWilborne 108]

Also only used the wireless for editing and monitoring programs. No messaging between PLCs

[DanW 41]

The purpose of a steel enclosure is to keep people out, electrical stuff in. Steel enclosures do a great job of keeping the radio waves inside the enclosure, too. Plastic (fiberglas) enclosures are transparent to 900MHz and 2.4Ghz ISM band signals. It is to be expected that a signal will never, ever get out of a steel enclosure with the doors closed. Paying more will not buy a wireless device that can transmit its signal through a solid, closed steel enclosure. The correct installation for wireless devices is to mount the antenna for the wireless device outside the enclosure. If the device has an integral antenna, then that means having the device outside the enclosure and wiring power and its data signal to it, or mounting the device in a fiberglas enclosure. Dan

[BobLfoot 301]

And here I thought the bosses jsut wanted to be able to hear me banging my head against the door when tings go wrong in the program.

[TimWilborne 108]

Actually the signal will go through an enclosure with no problem. I have gone through an enclosure and two 22 gauge steel walls at about 100' on a normal basis. Massive steel equipment and concrete are the biggest problems I had

[DanW 41]

Then you're making your money in the wrong business. Patent whatever it is that you've done, because wireless people willl pay to know. There's lot of effort and money expended on getting wireless signals out of or through steel enclosures (including all-steel buildings) that seeks an economically simpler solution. I suspect your signal found an opening: a fan vent, most likely, to get out of the enclosure and then bounced to get around the steel walls, or found an opening in the walls. The relatively short wavelengths where Wifi operates lends itself to finding access through quite small openings, but solid enclosures aer a death knell, and it seems to bounce well too. Concrete definitely attenuates, but the high gain antennae available on industrial radios can penetrate. Dan

[TimWilborne 108]

Nothing really special. They are mounted 12 x 12 x 6 Nema 12 boxes with the continuous hinge and gasketed door. I guess it could be squeezing through but have 3 of them doing it. Now the walls have plenty of holes in them from 40 years of abuse and are the thin galvanized decking you see on a lot of old buildings so it is possible signals are bouncing around to get from point A to B but the enclosures are sealed solid. BUT, now that you mention it, the shielded Ethernet cable, Beldin 7919A, that comes out of the enclosures is only in conduit about 20' up and then goes through a sealed connector and is exposed until it comes back down. Could this somehow be acting as an antenna?

[Nathan 7]

The subnet mask doesn't need to be 255.255.0.0, but that would probably be the easiest. If you wanted to follow convention you'd use the 172.16-31.*.* range for the non-routable Class B addresses (65,536 addresses). 192.168.*.* is the Class C range of non-routable addresses (255 addresses) and (by convention) you've chosen 3 subnets then wanted to merge them. If binary math isn't your forte do a search under "subnet mask calculator" in Google. For example here Edited 31 Oct 2006 by Nathan