PDA

View Full Version : Parallax PLC working with 220v outputs



Manuel
07-14-2006, 11:00 PM
Hello!
I want to work with the stamp plc and activate a resistive load (heating device) that uses 220ACV, as sensors I might use·some DS2760 with a more expensive thermocouple than the cable that's inclueded in the DS2760 kit. This is for some machines in my father's corporation. The only problem I have is the 24v to 220v interface which I need to be in a way that the PLC and the stamp in it is safe from any problem.
Best Regards

Manuel C. Reinhard

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Best Regards

Manuel C. Reinhard

Chris Savage
07-15-2006, 12:15 AM
Hello,

·· Connecting the 220V stuff is easy via an SSR.· Many have an input range well within the Stamp PLC.· The problem I see is connecting the one-wire device.· All I/O is isolated and you couldn't directly read the thermocouple.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)

Manuel
07-15-2006, 04:11 PM
Why won't the optical isolation let me read data directly from the DS2760's? Isn't it still 1s and 0s?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Best Regards

Manuel C. Reinhard

Chris Savage
07-17-2006, 10:23 PM
Manuel,

·· Here is the problem...Normally any Stamp I/O pin is bi-directional.· In industrial applications most devices are INPUT or OUTPUT.· When you optically isolate the input, it cannot be an output anymore in this configuration.· The 1-Wire protocol regarding this device requires you to send commands to it to retrieve values/information from it.· You have no way to do that currently.· Take care.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Tech Support
csavage@parallax.com (mailto:csavage@parallax.com)