Chapter 5 Temperature Measurement Module AH04PT/AH08PTG 5.1 AH04PT-5A 5.1.1 Overview The specifications for a temperature measurement module, the operation, and the programming are described in this section. AH04PT-5A is a temperature measurement module. It converts the temperatures received from its four thermocouples into digital signals. Users can select the degree Celsius or the degree Fahrenheit as a unit of measurement for temperature. 5.1.2 Characteristics (1) A sensor is selected according to practical application. Pt100/Ni100/Pt1000/Ni1000 sensor (2) High-speed conversion Two-wire/Four-wire configuration: 150 ms/channel Three-wire configuration:
300 ms/channel (3) High accuracy Conversion accuracy: The error is ±0.5% of an input. (The ambient temperature is 25±5°C.) (4) Disconnection detection When a sensor is disconnected, AH04PT-5A gives an alarm or a warning. (5) PID control An object can be maintained at a desired temperature through a PID control action. (6) A module can be set by means of utility software. HWCONFIG is built-in utility software in ISPSoft. Users can set modes and parameters in HWCONFIG to complete hardware configuration without spending time writing a program to set registers corresponding to functions. 5.1.3 Specifications Electrical specifications 5-3 Number of analog 4 inputs Three-wire configuration:
Pt100/Ni100/Pt1000/Ni1000 sensor, and 0~300 Ω input impedance Two-wire/Four-wire configuration: Pt100/Ni100/Pt1000/Ni1000 sensor, and 0~300 Ω input impedance Pt100: DIN 43760-1980 JIS C1604-1989; 100 Ω 3850 PPM/°C Pt1000: DIN EN60751; 1 kΩ 3850 PPM/°C Ni100/Ni1000: DIN 43760 Applicable sensor Supply voltage 24 V DC (20.4 V DC~28.8 V DC) (-15%~+20%) Connector type Removable terminal block 25°C/77°F: The error allowed is ±0.5% of full scale. -20~60°C/-4~140°F: The error allowed is ±1% of full scale. Overall accuracy Two-wire/Four-wire Four-wire configuration: 150 ms/channel Three-wire configuration:
300 ms/channel Conversion time An analog circuit is isolated from a digital circuit by a digital integrated circuit/an optocoupler, and the analog channels are isolated from one another by optocouplers. Isolation between a digital circuit and the ground: 500 V DC Isolation between an analog circuit and the ground: 500 V DC Isolation between an analog circuit and the digital circuit: 500 V DC Isolation between the 24 V DC and the ground: 500 V DC Isolation