wireless switch

[maintenanceman38]

I need to tell a pump to turn on or off from a great distance about 4000 feet. The plc I am using for controls, (DL-05). Has it's only slot used up. That much wire may be too expensive and all i have is 20 ga. The voltage loss may be too great. I would like to use a Roving Networks Wi-Fly module in adhoc mode to transmit a signal. I can use a repeater to boost the signal. and a Wi-Fly module to receive. Can the transmitter be in adhoc mode and have a static Ip address? does anyone know if this can be done and how?

 

[iant]

i think you might be better with a different frequency for remote switching.
http://www.elsema.com/ or similar.

 

[maintenanceman38]

I can't seem to figure out how to edit my post so i will reply to my own thread.
Can i use X-bee modules for point to point serial communication instead? or some other industrial module? I thought of the Wi-fly because I already have one.

 

[iant]

i am not sure - But the frequencey is the answer.
2.4Ghz as with 5.2 Ghz is the standard wifi ranges - these need to work with repeaters for large areas.
27 Mhz (the old radio toy) has a really long distance.
but check the Elsema web site there is some realy handy info there and
maybe 2.4 Ghz might work

 

[maintenanceman38]

I will check monday if we can order from the central texas distributor. I like the 151Mhz module as I can tell more pumps to come on if demand is not met in a certain time. And it has a long range so I do not need a repeater. But setting up a new distributor takes about a month. That is why I would like to go with X-bee or Rn-xv if possible.

 

[Mickey]

Two more options

http://www.bannerengineering.com/en-IN/products/60/Wireless-I-O/829/Discrete-I-O

http://www.controlmicrosystems.com/products/accutech-wireless-instrumentation/io/

 

[danw]

You're fortunate to live in the US where the ISM license-free wireless band allows frequency hopping wireless in the 900MHz band, which is simply ideal for industrial data - good punch through, good propagation. Most of the rest of the world can't use 900MHz.

A pair of Banner 900MHz Performance DX80 radios, one gateway, one node, do discrete or analog wired in-wired out. At 4000 feet distance, I'd use a high gain antenna.

I would think twice about 2.4GHz at 4,000 feet distance. It's doable, but the fade margin will be less, atmospheric moisture is more problematic, and is far more suspectible to WiFi type interference.

Anything with the word "Bee" in the name makes me think it's a zigbee derivative, designed for short-haul, low distance, meshing repeater, intra-building use. But you're the one with the experience.

 

[Lancie1]

I like the wireless module proposed by Mickey, cheap, easy, using the frequency-hopping spread-spectrum method, and not susceptable to an internet break-in (as would be a Wi-fi connection).

 

[maintenanceman38]

The banner solution looks goos and easy to setup and use but at $900 for the kit I don't think they will let me do that for now. The accutech I cant find prices for it yet but it may not be feasible because it needs a rs-485 or re-232 for the baseband radio to work. and I did mean zigbee not x-bee. I found zigbee pro xbp9b-***t-002 has a range of 1200 feet and 3miles with a high gain antenna. But I have no experience using zigbee. Only roving networks Rn-xv module

 

[mendonsy]

How important is this pump to the overall scheme of things???
If it is important you might be better off to spend the money now than risk the chance of a failure later on.

 

[maintenanceman38]

The pumps are very important right now they run 24-7. We already have to buy $800 worth of sensors so I cannot justify another $900 until the concept is proven. Eventualy I will replace this with the banner or elsema because they are reliable and well engineered. I just want to know if it is possible and if not they would just have to wait for the new budget. But thanks keep the suggestions coming as I am going to look at every possibility. and who knows they might let me order the kit.

 

[diat150]

what about using another plc at the pump site and doing messaging between the two over a radio network? that seems like a safer option because you could have a heartbeat between the two to verify communications. (not familiar enough with the dl05 to know if it supports messaging)

 

[maintenanceman38]

There is a Dl-06 plc(automation direct) controlling the well house and I do have room on that plc for a mod bus or other module. But the Dl-05 only has room for one and that is used for the tower sensors. But this gives me an idea. There are 2 telephone type jacks used for programming and HMI communication. I am using one for the HMI but i wander is I could use the other for rs-232 the same cable used for programming?

 

[maintenanceman38]

I found it a F2-unicon module lets me use this jack for rs-485 or rs-232. now what do you suggest?

 

[jkbarik]

thanks very much for your reply.

J K barik
Mumbai