Concept - PLCS RTD
- CIMON (Unlicensed)
Analog Value - A
Consecutively changing amounts such as voltage, current, temperature, speed, pressure and flow rate are called Analog amount. Temperature, for example, is consecutively changing by time as shown in Figure 1-1. However, because this consecutively changing amount can’t be directly inputted to PLC, thermocouple input module makes it possible to convert temperature into digital amount for PLC.
Digital Value - D
Non-consecutively changing amount like numbers such as 0, 1, 2 and 3 is called Digital amount. The signal ON and OFF is expressed by digital amount of 0 and 1. BCD value and binary value are also Digital amount.
CPU module cannot input analog value directly to calculate digital amount. Therefore, analog value should be converted digital value to be inputted to CPU as Figure 1-3. In addition, digital value in CPU needs to be converted into analog value in order to output analog value.
Platinum and nickel thermo resistor
This is a sensor to detect temperature as a resistance..
A platinum thermo resistor, Pt100 and jPt100 display 100.00W of output for a temperature of 0oC
A platinum thermo resistor, Pt1000 displays 1000.00W of output for a temperature of 0oC
A nickel thermo resistor, Ni1000 displays 1000.00W of output for a temperature of 0oC