olle_hansen
Member
Hello,
I want to make a rather simple control for fans in a basement. The point is to evaluate the inside and outside temperatur, relative humidity and absolute humidity.
To do this I need a PLC and some sensors.
I'm thinking PLC Logo!8, due to the fancy display.
Humidity sensors are hard to figure out, since they can be very expensive. However, I think this will be suitable: http://www.temcocontrols.com/products/sensors/16/humidity-temp-transmitter.htm
Only a few humidity sensors have output for "Absolute humidty", hence they calculate the values themselves. I think it's better to have only temperature and relative humidity to the PLC, and then calculate the absolute humidity in the PLC.
Formula for absolute humidity:
Besides the inputs (temp+RH) the formular needs the natural logarithm "e".
Can the PLC Logo handle this formula?
Also, 4 analog inputs are needed. Instead would it be possible to use modbus?
Modbus communications port: RTU, 19.2/9600 Baud.
Any suggestions?
I want to make a rather simple control for fans in a basement. The point is to evaluate the inside and outside temperatur, relative humidity and absolute humidity.
To do this I need a PLC and some sensors.
I'm thinking PLC Logo!8, due to the fancy display.
Humidity sensors are hard to figure out, since they can be very expensive. However, I think this will be suitable: http://www.temcocontrols.com/products/sensors/16/humidity-temp-transmitter.htm
Only a few humidity sensors have output for "Absolute humidty", hence they calculate the values themselves. I think it's better to have only temperature and relative humidity to the PLC, and then calculate the absolute humidity in the PLC.
Formula for absolute humidity:
Besides the inputs (temp+RH) the formular needs the natural logarithm "e".
Can the PLC Logo handle this formula?
Also, 4 analog inputs are needed. Instead would it be possible to use modbus?
Modbus communications port: RTU, 19.2/9600 Baud.
Any suggestions?