If I need to monitor two normally-open switches and log when and how long they are closed, I can do this with a DS9490R USB bridge and a D22 Channel Digital I/O 1-Wire Card ... correct???
The software to monitor is no problem for me but I am new to data acquisition and monitoring.
Thanks in advance!!!
What is a "D22 Channel Digital I/O 1-Wire Card" ?
Yes, a 1-wire DS9490R will connect a USB port on a computer to a 1-wire integrated circuit such as a DS2450 that could be used to sense contact closure.
Depending on your application, you may find the 1-wire system to be neither very robust nor inexpensive compared to a $5 (shipping to US included ) USB to 25-pin parallel printer cable/converter.
Search eBay for: usb parallel
Visit:
HTH ... Marc Marc_F_Hult
Even if you go with 1-wire (BTW, I like Marc's Idea), a couple of DS2401's would do it.. They are 1-Wire "ID" devices, and based on the switch are on or off buss, the switch state is known. In a TO-92, they could be right on the switch and just require the net and GND.
I use this set up in a few areas of the house, but I also have other sensors on the buss (temp) and DS2405's to have LEDs display things!
Another option if there is a free serial port is to use DSR and CTS (or DTR and RTS, depending on your perspective!) to be the state of the two switches
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