8-Channel Sensor Input Temperature Transmitter's Working Principle and Structure
NCS-TT108 collects thermo resistance and thermocouple signal, which is converted into fieldbus signal after arithmetic and handling, and achieves temperature measurement functions.
NCS-TT108 mainly consists of two parts. The hardware structure is shown as picture.
1. Communication board: It is the core component of smart temperature transmitter. It provides fieldbus communication, control, diagnosis and maintain.
2. Instrument board: It connects 8-channel temperature transmitter, converts the temperature sensor’s signal to digital signal and finishes temperature arithmetic. It provides the signal to communication board via isolation communication interface, connects the bus and converts to communication board.
Principle Introduction
Instrument board interface is connected to field bus. Via pressing, over-current protection to communication board, which is in parallel with stable-volt circuit, to produce 3.3V direct current. Via four groups of isolation—DC/DC isolation module, it achieves stabilivolt again, and provides volt to four groups of temperature collecting module. Every group of temperature collecting module includes two-channel temperature converting unit. Each single channel alone can set sensor type and thermo resistance wiring; Via four magnetic isolation component, communication Board's master control circuit serial communicates with four groups of collecting module, and can set and read temperature value respectively. Four groups of temperature collecting module are isolated respectively. Within collecting modules, two temperature input channels are not isolated.
Communication board indicates the working state of temperature transmitter via ten indicator lights. Two DIP switches set configuration. Master control circuit visits circuit via media, and communicates with field bus.
