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What components do I need for a wireless Ethernet network between ControlLogix and 1734 Point I/O PLCs?

Article Number: 471 | Rating: Unrated | Last Updated: Thu, Aug 20, 2015 at 7:55 PM

All of our Ethernet radios will function as transparent Ethernet bridge devices. We would recommend one of our "Industrial Hotspot" radios"

RLXIB-IHW: 802.11a/b/g Industrial Hotspot
RLXIB-IHA: 802.11a Industrial Hotspot
RLXIB-IHG: 802.11g Industrial Hotspot

Links to the product page for these products: http://www.prosoft-technology.com/content/view/full/12109

Which radio you choose will depend on the particular needs of your system. They can be categorized based on:
1. Bandwidth. How much traffic must be supported by the wireless system?
2. Distance. What is the anticipated distance that must be spanned by the wireless equipment?
3. Frequency. All of our wireless products are license-free equipment. We have products that operate in one or more of the following frequency bands
    a. 900MHz Band
    b. 2.4GHz band
    c. 5GHz band
The basic question would be: What other wireless equipment will be operating in the vicinity of the intended application? If you have not already done so, you should investigate what wireless equipment is already in use (or is planned) in the vicinity of your application. This may reveal that you have too much existing activity in a given frequency to allow additional RF traffic in a particular band.

I. Bandwidth. Since the 1734 PointIO is used more bandwidth would be needed than the RLX-IFH9E. This radio is capable of great distances (20+ miles with the right antenna), but has limited bandwidth (350 packets per second).
Note that Rockwell has provided some very good tools for estimating your bandwidth needs. Refer to the Rockwell document, "EthernetIP Performance Application Guide", publication number enet-ap001.pdf. Also, we would recommend using the Rockwell "EthernetIP Capacity Tool". This is a free software tool that will calculate the "packets per second" (pps) load based on the equipment you intend to use in your application. This tool can be downloaded from the following web page:
http://www.rockwellautomation.com/solutions/integratedarchitecture/resources3.html#enetpredict

It is more than likely that you will need one of our Industrial Hotspot products:
RLXIB-IHW (1000pps), operates in the 2.4GHz or 5GHZ bands, distances of less than one mile
RLXIB-IHA (1000pps), operates in the 5GHz band only, distances of up to one to 2 miles.
RLXIB-IHG (1000pps), operates in the 2.4GHz band only, distances of up to one to 2 miles.
RLXIB-IHN (1500 to 4000pps) , operates in the 2.4GHz or 5GHZ bands, distances of less than one mile. Note that if the higher "pps" is needed, the range will be very limited (less than 100ft)
NOTE: THE DISTANCES MENTIONED ABOVE ASSUME PROPER ANTENNA SELECTION AND PLACEMENT WITH MINIMAL INTERFERENCE FROM EXTRANEOUS SOURCES.

II. Distance. The distance capability of a given wireless system is a function of transmitting radio power, antenna and cable components, antenna placement, and sensitivity of the receiving radio. Frequency plays a part in this also. However, other criteria will most likely be an over-riding factor (existing RF traffic, bandwidth, etc...). Note that all remarks regarding range assume good line of site. This means that you must be able to stand at one antenna and actually see the other antenna(s).

III. Frequency. As mentioned before, it is wise to know what sort of RF environment exists at the intended application site.
You can use a laptop computer with a 802.11b/g module and a wireless discovery tool such as "NetStumbler" to determine if there is other 802.11b/g activity. "Netstumbler" is a free software tool available at the following web page: http://www.stumbler.net/ . This tool will use your computer wireless module to scan for any 802.11 type activity in the area near the computer. Note that there can be activity in the 2.4GHz or 5GHZ that is NOT 802.11 type activity.
In this case, the discovery tool will not reveal the presence of this extraneous RF signal. You may want to consider a spectrum analyzer such as the "AirView2" product from Ubiquity (http://www.ubnt.com/airview ). This is a fairly inexpensive analyzer (less than $100.00US) that would detect any RF activity in the 2.4GHz band.

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