Thermocouple, RTD, Temperature monitoring is central to the majority of
data acquisition systems, be it to save energy costs, increase safety,
reduce testing time…whatever your reasons, you will need a device to
measure the temperature - a temperature sensor.
How to Use Your PC to Measure Temperature
Thermocouples, resistance temperature devices (RTDs), thermistors and
infrared thermometers are all types of temperature sensor. Which you
choose depends on factors like your expected maximum and minimum
temperatures, the accuracy you need and your environmental conditions.
752-RTD: RTD Resistance Temperature Measurement, Digital I/O, Counting, Analog Output
- Measure temperature using RTDs or Pt100 sensors, and voltage signals
- With extra hardware monitor thermocouples and strain gauge bridges
- Includes the powerful yet easy-to-use Windmill software for Windows: no programming required
- Connect up to 8 USB units to one PC
Here is a way you can learn, How To Interface PC to the Outside World.
Temperature Control with a PC
Based on the above the Octagon computes a sensible heating/cooling
current value and transmits a corresponding analogue signal to the
current control electronics in the TC-box.
The current control electronics control the current provided by a big
external power supply flowing through the peltier heating elements
according to the signal received from the Octagon.
delabs Notes
This is a project that will help students learn both hardware and
software aspects of a control system. Here you can test out an
automation program on a PC with minimum external hardware.
When you implement in the field, the system has to be a dedicated real
time uC based product on custom firmware. Systems with OS + Software
combination are not known to be reliable in Process Control. But OS +
Software is good for Supervisory Systems which get their data from Real
Time Controllers.
So a front end controller must be Rugged, Non-PC based and Non-OS based
embedded system. With a Robust and Compact (means fast) firmware.
The firmware should be Polling or Interrupt based but with both internal
and external watchdog. Most important a Power supply Management that
resets system properly over Brown-outs and Black-outs. Even today some
Embedded Systems i have to turn off and on after power resumes.
Don't Forget, Multiple Watch Dogs and Multiple Power Management for
graceful start of system !! Use one big SuperCap if you want. Else
people will go back to Thermostats.
