|
| Ek's Home | Forum | Chat | Electrical Links | |
| Subject - 4-20mA over Bluetooth | |
| rafiki69 | Does anybody know of any products that are capable of converting 4-20 mA signals to bluetooth. I found some products but they were the size of a cable modem. I was looking for something small like the size of a deck of cards. It would be nice if it were a pair like a transmitter and a reciever. And even better if you could monitor the connection from a PC. |
| JimmyDee | When I left the field of instrumentation, bluetooth wasn't invented yet. You will have to be helped by Scott or someone else. With that said, I would like to understand the application you need the bluetooth for. Are you just monitoring, like with a Palm or something similar, or are you actually controlling a process? Jim |
| Scott Vickrey | I assume you want to use Bluetooth and a small device so you can carry it all in the same case with your laptop to the field. My first bit of advice is to use WiFi instead of BlueTooth. This will open up many possibilities. You'll find more information and equipment going this route. Not to mention WiFi can easily patch in to existing ubiquitous WiFi networks allowing access from any where in the world. I was unable to find a small device. I know there are many people out there that can make one using a loop powered single or two chip solution now your talking really small. I bet if you looked hard enough you can find one commercially available. I spent a few minutes and here's the best I found: SensorBlock It's about the same size as what you described but with all it can do I think you would want to see it. It can log 4-20mA, 0-5V, dry contacts, internal temp, thermocouple and RTD inputs and can even interface to Modbus. With 8 input channels sampling at 200Hz with a resolution of 10 bits. It's software will graph all that out and store it for you. Wow. I wish I had one. I'm confident with a rigorous search you can find a smaller simpler device but not too sure about Bluetooth. Bluetooth verses WiFi can be compared to USB verses Ethernet respectively. As that is what they are designed to replace. Tip For Mining Hard-to-Find Info in a Search Engine: Try searching for phrases you expect to be in the page you are looking for instead of a product description. Like "loop powered" and "WiFi" and "4-20". Find the most relevant page and look for key phrases you expect to appear in your target page. Make slight targeted modifications to these phrases and repeat the search. Before long you will have found the phrases that will bring your nugget to the surface. |
| Chris Clement | It's funny how the protocols keep changing to obsolete good equipment. My cousin, Wm. Clement was selling a packet radio device that sent several 0-5v channels (easily converted to 4-20ma) and several closures (now called Booleans). The darned thing was smaller than a plastic cigarette lighter and it was made in the mid '90's DOS era. It was called the MIM but I don't know what that stood for. |
| Brad Selmon | quote: The best product on the market is from Elpro. www.elprotech.com This is pretty industrial, but very reliable. |