Allen Bradley Compactlogix to Wifi Network

[dkc1971]

Good afternoon,
I'm building a test station for temperature mapping that will log 12 data points to SQL via Open Automation Software. This station will need to be mobile as our equipment being tested is quite large and in varying locations in the test area. My question is are there any way to do wifi communications from the PLC to the network SQL server without having to pull a data cable. We have power in the area that is readily available. I have the OAS software running on a desktop at my desk that will handle all the data control. Thanks in advance for any help you can provide.
Darron

 

[Operaghost]

Distance, security, and interference issues aside... the easiest method to add wireless to a CompactLogix is to have a wireless access point (WAP) at the control panel and run a physical cable from the PLC to the WAP.

If your company already uses WAPs then already you have a good resource for getting it setup without interfering with any other Wi-Fi networks.

OG

 

[marv_tech]

I've used devices in the past called Ethernet-Wireless bridges. If you have robust production Wifi, I think this is a decent solution for you. Things can get a little weird at the extremes so it would be worth testing in some areas with weak signal to see if it breaks gracefully (some protocols will, some protocols won't.) This would be the cheapest route I can think of. You'll find a ton if you google for "Ethernet to Wifi Bridge". I'd steer away from the cheaper/multi-purpose ones as they can be very frustrating, ideally go through an industrial supplier where you can get setup and IT help.

Here is an example:
https://www.silextechnology.com/connectivity-solutions/ethernet-2-wifi-bridge/br-500ac?hsLang=en-us




In the same vein, if your wifi is not robust, some companies do ethernet over radio. So you'd have a transmitter and receiver, you could move the transmitter to the closest jack when you get out of range. I don't have personal experience in this area but I know Digi makes one that will do up to 200kbps (not sure if it would work for your usecase.)

Some examples:

https://www.digi.com/products/embed...eways/xbee-pro-900hp-rf-modems#specifications


https://www.anybus.com/products/wir...wireless-bridge-ii-ethernet?ordercode=AWB3000


Another possible option (although less likely in most factories) would be powerline adapters. These give you an ethernet connection at any 110v outlet.
If your grid is fairly clean and mostly running from the same substation, this might be more reliable than your wifi. For what it is worth, I found in my plant that powerline adapters are worse than useless due to the way we do distribution. Even if our distribution was better, there is so much noise from motors that it likely wouldn't work well.

 

[johnd_125]

I had an application that sounds similar to yours. The customer needed to monitor 24 temperature points in a heat treat furnace every 3 seconds over several hours and store this data in an excel file. This data was kept for traceability purposes and for temperature controller calibration.

They did this calibration procedure to each of 20+ furnaces every few weeks. In the past they had some Yokogawa Darwin temperature input modules that connected to Yokogawa software running on a laptop computer. It was all on a mobile cart they pushed around to each furnace. The setup created a csv file for them. It worked for years but it was outdated, having issues, and they wanted me to upgrade.

There was an existing Wonderware system in place to run the furnaces so I planned to use it to capture the data to the SQL database and create the file they wanted. I connected an HMS Anybus bridge to it. I built a new box to go on their cart with a 2nd HMS Anybus Wireless Bridge on it. The box had some Automation Direct Thermocouple modules that had Ethernet/MOdbus TCP capability. The cart/box did require 115VAC power but they were accustomed to plugging their other cart into power and that wasn't an issue. The facility was about 300 ft. long so I placed the stationary antenna such that it was midway in the facility and would have line of sight with the cart, at all times. So, the Wonderware computer had ethernet access to this mobile cart. It was simple to set up and has been nearly 100% reliable.

Full disclosure: I had another HMS Anybus wireless bolt/bridge on some equipment at about the same time. It was used to connect a CompactLogix to some 1794 Flex I/O. It dropped communications too much. I jumped through all the hoops that the LD and Anybus put in front of me, trying bluetooth, wifi, various channels, moving antennas, etc. but nothing solved it. I eventually gave up on it, and them, and ripped it out. But I waited too long, got it dirty, and they renegged on the warranty. So I'm stuck with it. For grins, I connected it here in my office and using a wifi analyzer I can see it has the weakest signal of anything I have running. No wonder it flaked out. So, use wireless with extreme caution...

 

[dkc1971]

Thanks everyone. I'm going to give these a try and post back when i see what happens.