temperature and humidity sensor over distances

[Grugh_Mike]

My primary aim is to monitor the temperature and humidity condition in my facory.

The dimension of the factory is 200X400 meter.

So kindly help me out how to install and take out the data read by different RH/ T sensors installed throughout the plant.

Will the data through RS232 interface travel through such long distances or are there any signal boosters for RS232 cables.

Can data from different sensors be read using a single RS232 interface?

Are there any specific sensors to meet this demand?

Kindly help me.

Thanks in advance.

[RavensFan]

RS-232 is only good for about 50 feet.  Also, it is intended for point to point communications, but it is possible to connect multiple device to RS-232 only if they behave very carefully such as responding to a request for data only when they are specifically addressed in a message.

For the distances you are talking about, you'd need to use RS-485.  That is good for longer distances, (about 1500 ft) and are designed for multi-drop so that multiple devices can be on the same set of wires.

Another alternative if your plant is wired enough is to use the plant's LAN and get devices that have ethernet communication.

And yet another option is to get sensors that use a wireless protocol to communicate such as NI's WLS modules.

[SnowMule]

Yea, I'd go the LAN route if possible.  Wireless gateways work pretty well for making a wireless network wired in an area.  There's a few Ethernet-to-RS232 adapters available. 

Cabling is inexpensive, and probably already in place.  Personally i'd try to avoid wireless if possible in a factory environment... lots of RF noise in that situation that makes a good wifi network tricky to implement.

[Grugh_Mike]

Thank you for all your replies.

I have decided to choose the ethernet type sensors.

Specifically after browsing through the different models; i have come up with the sensor from Microgoose.

Attached is the link to the Microgoose (T/ RH/ DP) sensor. link: http://www.itwatchdogs.com/product-detail-microgoose-9.html

The device can be fully configured and made functional using a web browser.

But it does not have any Labview support. Is there any possible way to get data out of the device to LV frontpanel?

Kindly help.

[DavidBoyd]

Yes, any device on a network which functions as a web server can be accessed by a PC on that network running LabVIEW. The LabVIEW TCP primitives can be used, or you can use fancier (though perhaps more platform-dependent) methods such as .NET.

I've no experience with MicroGoose, but I've used SensaTronics EM1, E4, and E16 devices, writing a bit of LV code using TCP Read, to query them. These devices also work well with Intellipool, a commercial network management/monitoring package.

Good luck!

Dave