wireless comms

Ok.here goes. I need to connect 2 by micologix1200 plc's,approximately 200m distance between them with wireless ethernet. Then connect a SLC505 and a compactlogix,approx 500m dstance between them,with wireless ethernet. They will all in turn connect to a new compactlogix central contrl station. Any ideas on best practices? What do i use? does rockwell have the hardware and software?

Why wireless?

I think you would have a lot of issues if the network was in a manufacturing plant due to the noise and that distance.

You would be better off just running wires and making your own network

Rockwell Automation does not sell radiomodems or wireless Ethernet gear, but several of our partner companies do.

This sounds like a good application for high-power WiFi products from Data-Linc or Prosoft.

If you don't have a line-of-sight path between your stations an the central station, you may have to try a mesh network or use 900 MHz radios that can transmit much further than 802.11b or 802.11g radios can.

The serial devices can be connected to Ethernet using a device like the A-B 1761-NET-ENI, the Digi One IAP, or the Data-Linc Net620.

Do not expect the MicroLogix devices to act as data concentrators or master polling stations. Use the central controller to read and write from the MicroLogix.

The best installations I have seen make use of a radio survey by a competent consultant who can advise you on antenna selection and placement and transmitted power requirements.

Hi Genius
Wireless because the site is a waterfront and i have installed all the PLC's over the years on pedestrian crossover bridges (hydraulic bridges). The need is now for a centralised control station to control all the bridges from a central point,with ethernet video cameras also included.

Thanks Ken.
Line of site is guaranteed. I am going to install the new compactlogix as the master. I am looking into the Prosoft line and was hoping someone had done something similar before and steer me in the right path.

monsam said:

Wireless because the site is a waterfront

Click to expand...

Ah!... its hard to stop the boat props from cutting the wires

Esteem Modems seem to work very well. I have 6 radios over our waste water treatment plant and substation. They work well outside and are fairly easy to set up. Esteem P/N: 195Eg

monsam said:

Hi Genius
Wireless because the site is a waterfront and i have installed all the PLC's over the years on pedestrian crossover bridges (hydraulic bridges). The need is now for a centralised control station to control all the bridges from a central point,with ethernet video cameras also included.

Click to expand...

I live on a boat in the Northwest USA where we have a tidal range of about 12 foot. The most common for foot traffic is to hard attach the ramps at the shore end and on the dock end it just rolls back and forth to allow for tide.

I am curious why you need hydraulic control. The only place I have seen that is on the state ferry auto loading ramps (and a few others mostly involving ships or barge loading).

Wireless would be a good choice in this case but you still need to run power conductors so why not run control cable also in the same bundle or run (NOT in same conduit to minimize EMI). I guess it comes down to what is best long term (life cycle) cost solution.

With good transmitter/receivers hardened for environment ie wind rain salt spray it should work well.

The other thing to ensure is that you will not have other transmitters setting off your equipment. There have been cases of garage door openers for instance interfering with industrial radio controls which have resulted in a few accidents.

Radio control is often a good choice and I have seen it work very well. Just takes careful design and selection of equipment.
Dan Bentler