Remote Control via Phone or RF

[peebee]

I have a project where we have been requested to investigate remote lighting control. This is to switch some outdoor lighting located roughly 400 feet away and across a river from the building where central control will be located. Design criteria include:

* Centralized control from the building is required.
* We cannot cross the river directly with a cable or fiber.
* The remote controls need to be weatherproof; a heated weatherproof enclosure could be easily provided but we'd like to avoid air conditioning. Ambient temps up to 105F.
* Minimum control requirement is one discrete on/off signalto be transmitted from the building.
* A desireable option, but not required, would be the ability to monitor up to perhaps 4 remote alarms for annunciation at the building.

Two solutions have been proposed:

1. RF. We've generally been steering away from RF due to concerns over reliability and possible interference.

2. Telephone & modem system. Conceptually this seems to be the best solution. However, discussions with several vendors have not been very productive.

Any thoughts? Vendor recommendations? Unexplored solutions? Have we sold RF short?

Thanks in advance.

 

[busbar]

If the phone line is a dry pair, then

http://www.solidstateinstruments.com/products.htm

"tone products" may do the job.

With all the rage for wireless-network stuff, 2.4GHz gear with directional antennas as part of a PC network, incorporating industrial-control I/O components like Opto-22 stuff could be another approach.

 

[Lewish]

Take a look at a microwave product called GEMLINK by General Electric. It is a bi-directional link at 23GHz. The whole unit looks like an average sized floodlight. Weatherproof. Reliable. I know of units that have been in the field for 20 years.

 

[djs]

Hello;
RF over short distances can be very reliable. What are your cost constrasints? perhaps a small PLC (AB Micrologix?) and an unlicensed spread spectrum radio (MDS9810?) would work. If you want more details give me an e-mail.

 

[peebee]

How reliable is "very reliable?" -- are we sure RF would generally work every day for the next 10 - 20 years? Occasional problems would be acceptable, this is not a critical application, but on the other hand it is a very visible application (ie, visible to top managment types).

I don't have a good feel for costs yet, I'm guessing our solution should be in the $1k to $10k range.

So far I've been calling mostly lighting control vendors. I'm starting to think industrial control vendors (PLC's) or building management system vendors are where I should be looking.

Any further details you have to offer would be appreciated. Email is fine, but I like the idea of using this site. If you are a vendor and would like to discuss specifics, please post your contact information.

 

[Lewish]

peebee, the GEMLINK is as reliable as your power source or phone line. Your power can go off. Your phone line can be cut by construction a mile away. Nothing is 100% bullet proof. The GEMLINK, last time I looked was about $1600 for multiline data and 1 video.

 

[peebee]

I'm looking into it Lewish, thanks. I understand your comments regarding bulletproofing this. I appreciate the help.

 

[automatic2]

A friend of mine just hooked up a monitor system for his oil pumping station. From his home he dials out on this laptop to a cell phone at his well site which has second laptop. Security software on either end drives 4 different monitoring cameras at the well site. This gives him realtime images of the site which is some 400miles away. I'm sure the system , or similar could be modified for different I/O.

 

[markac]

With telephone services, an autodialer could be used at each end for remote control. Check out

http://www.racoman.com/guardit.html

This unit is capable of one control output and maybe 4 alarm inputs at the location of the remote lighting.

 

[jsalls]

You might try X-10 Automation for a solution. They do a lot of home lighting control work, but also have telephone dial-up equipment for monotoring the status of equipment. I have used some of their stuff to automate my home (i.e. have a remote control to turn lights on and off) and it has been pretty reliable although I haven't had my house up to 105 degree's. They should be at the low end of the range of costs. Their web address is

http://www.x10.com

Good Luck!
John Salls
Applied Vision Systems, Inc.

 

[peebee]

Lewish, I've scoured Google and GE.com pretty extensively for Gemlink, and have found very little in the way of substantial information. Nothing at all on GE.com, and only brief references from Google. Any idea where I can find out more?

 

[jraef]

For consideration of reliability in RF controls, take a look at radio crane controls like Cattron, Control Chief and Telemotive to name a few. The reason I say this is that they must deal with life/safety issues on crane controls, and they operate in reserved bandwidths or have redundant error checking so as to avoid problems with interference as much as possible. They will not be the cheap answer, but I would trust them. I once worked on a ferry boat system where we used them to transmit dock leveling controls to the shore as the boat approached. Flawless performance in all weather conditions.

For phone control. I found these to be reliable as well.

http://www.sensaphone.com/pages/comparison.html

Quando Omni Flunkus Moritati

 

[djs]

Hello;
We make radio RTU packages for the water and wastewater industry. Generally speaking a properly setup system will work for 10 years or more. Typical outages occur during thunderstorms. You should be able to get a complete package for under $5K. If you need more info, give me an e-mail.

 

[peebee]

djs -- what's your email address?

 

[peebee]

Update: Well, now I'm slowly coming to believe that RF may be a better solution, particularly after digging into some of Jraef's leads -- thanks. Sensaphone, by the way, also put me on to

http://www.omnexcontrols.com

, they make a slick "cordless wire" product that can pass both discrete and 4-20mA signals in a relatively inexpensive package.

As simple as this thing sounds in concept, it's amazing what a headache it's been researching the options. Thanks again to everyone for your input.