Hi Does anyone know of any 'Sensors' (such as Ph, float switches, temperature etc), that are available to be connected to a PC, and their values read via the .NET framework??
Thanks
Hi Does anyone know of any 'Sensors' (such as Ph, float switches, temperature etc), that are available to be connected to a PC, and their values read via the .NET framework??
Thanks
Quite a few PID's are available using industrial ethernet, and almost anything can be connected to one of these. Most 'sensors', will be relatively 'low level' devices returning just a voltage or 4-20mA signal. Add a module like this, and they become easy to read.
Best Wishes
Thanks for the reply.
Sorry, I'm a novice on this stuff, can you please confirm what a PID is please.
I know most of these sensors come with a BNC style plug. Is there a device that can read the voltage from a BNC device??
Do you know of any USB devices that would be useful??
Thanks
Paul Aspinall wrote this in :
BNC is just a connector. It is used for everything from 10Base2 (you know that old ethernet, eh?) to 'scope probes and RF applications
-- MVH, Vidar
The old geezer definition of PID was Proportional/Integral/Differential. This was a gadget that would generate an output feedback that was Proportional to the input, but there might be tiny difference between the input and output, so you would Integrate the difference between input and output and use that too to minimize error. Then there could be differences because of sudden changes in the input, and you used the Derivative to accomodate that too.
I'd use a BNC jack and solder whatever I needed to the other side of that.
If you were looking for cheap,
Radio Shack has had multimeters with PC interfaces for a little more than that.
Test & Measurement World magazine had an article a few years ago on budget measurement modules. This might be it.
It had a long list of companies in the $100 or so category for measurment cards.
There are a large number of microcontroller modules in DIN rails, built as 'PLC' modules. the simplest of these are commonly used for 'PID' control of servos, kilns etc.. these lack the sophistication (and cost) of the larger PLC controllers, but in most cases have the 'basics', of a programmable controller, a couple of digital inputs, and an analog channel. For what you describe, I'd look at these more basic modules, rather than their full size brethren. They are usually marketted as 'mini PLC', or 'PID' modules.
BNC is only a connection. You can put just about any plug you want on a sensor, but BNC is commonly used on the modules as well, when they support analog inputs.
USB, is a very 'not nice' interface in this type of enviroment. Seriously, many industrial modules will be built to survive 250v or more being accidentally attached. USB, does not provide the isolation, or ruggedness required in this sort of enviroment (there are some fibre-optic USB repeaters that are quite good, but expensive). It's 'range' limits, and lack of error recovery, also make it less than ideal. You can connect to an ethernet interface with USB, or RS485, and these are the signallign standards you are more likely to find.
Best Wishes
There's also
-- Rich Webb Norfolk, VA
I was using them when they changed their name. ;-)
-- ? Michael A. Terrell
Check out the Labjack for USB interface DAQ.. has both analog I/O and digital I/O, timers, counters, etc... Not as pricey as the National Instruments line, but not as full-featured either. Programmable using VB6, VB.Net, etc.
-- Dave M MasonDG44 at comcast dot net (Just substitute the appropriate characters in
Their USB-6008 is $145 and can do external triggered acquisition and can do digital IO during analog acquisition, something the LabJACK cannot.
Steve
USB with many sensors
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