K type Thermocouple Platinum resistance temperature analog channel isolation acquisition module PT100PT1000 MODBUS RTU RS485

• Overview

MB8ART8High-precision mixed-signal acquisition module, which can acquire analog quantity (±20mA,4-20mA,±15mV,±100mV,±1V),8Thermocouple(J/K/T/E/R/S/B/N),2Kind of platinum resistance (PT100,PT1000,CU50,CU100) And many other signals, and the signal type of each input channel can be combined at will. The collected analog signal data, through isolationRS485Interface output; module adoptsModbus-RTUCommunication, adaptable toPLC,DCSAnd various configuration software, etc.

Signal input, CPU, power input and RS485 communication electrical signals are isolated from each other, effectively suppressing various serial mode and common mode interference, ensuring data accuracy, and also ensuring the reliable operation of the module.

MB8ARTThe module is mainly used in applications where temperature acquisition and multiple analog input signal types coexist. It can be widely used in iron and steel smelting, metal heat treatment, chemical industry, metallurgy, glass processing, injection molding temperature control, tobacco, medicine, automatic complete sets of equipment, and so on.

• Features

  1. 8Mixed signal input (thermocouple, platinum resistance thermometer and analog quantity),The input signal type of the channel can be set according to your own needs.

  2. Thermocouple, thermal resistance and 4-20mA input have the function of detecting disconnection, which is convenient for on-site debugging and maintenance.

  3. Fully differential input, and each channel is isolated from each other.

  4. High-precision signal acquisition: High-precision twenty four-bit AD and voltage reference are used, and the temperature coefficient of the voltage reference is 10PPM/°C.

  5. Independent high-precision cold junction compensation, accuracy ±0.5°C.

  6. Safety: Signal acquisition, signal output, power supply, and RS485 communication electrical signals are isolated from each other.

  7. The standard Modbus-RTU protocol is adopted, and the RS485 communication signal output interface adopts double protection of overvoltage and overcurrent.

  8. The input signal type and communication format can be set by software.

  9. Power input polarity protection and overvoltage protection.

• Technical index

• Product appearance, terminal definition and status indication

  1. Appearance

1. 1. Terminal definition

1. 1. Module indicator description

      1. POW/SET;Module working status indication

Green light on: The module is working in the running state.

Red light on: module configuration parameters have been written, you need to cut off the power of the module again, and then power it on again.

1. 1. 1. TXD/RXD:Communication status indication

Green light is flashing: The communication receives data, but no data is returned.

Green and red lights flash alternately: the module is receiving and sending data.

Steady green light: The communication RS485 lines connected to DATA+ and DATA- are connected reversely or the wiring is disconnected.

• 1. Function description of the reset switch on the right side of the module

     1. When the communication parameters (module address, baud rate, check digit) are not known or the communication parameters are set incorrectly, and communication with the module cannot be established, the solution is to reset the communication parameters; we use a paper clip to press and hold the reset switch and do not let go After 5 seconds, the red indicator light of the module [POW/SET] will be on. Release the reset switch. At this time, the communication parameters have been reset. As long as the power of the module is turned off and on again, the communication parameters of the module have been reset.

     2. Communication parameters after leaving the factory and after resetting: address: 1, baud rate: 9600bps, parity: none.

• Module installation method

The front side of the rail installation The back side of the rail installation The effect of stacking and installation of modules Side

• Typical application wiring diagram

  1. Thermocouple (J, K, T, E, R, S, B, N) and voltage input (±15mV,±100mV,±1V)wiring

1. 1. ±20mAWiring with 4-20mA current input

1. 1. PT100, PT1000, CU50, CU100 thermal resistance input wiring

1. 1. RS485Communication wiring diagram

1. 1. Module power input wiring

• Various signal input
  1. Thermocouple input

     1. All channels can be directly connected to the thermocouple input, and the collected results can be directly converted into the actual temperature value. The built-in cold junction compensation sensor can automatically cold junction compensation for the thermocouple.

     2. 8 types of thermocouples, including J, K, T, E, R, S, B, N, etc. can be selected, and the corresponding channel is set to the corresponding thermocouple type when in use.

     3. The temperature data result is a 16-bit signed int type, and the actual temperature is the actual temperature after dividing the read data by 10.

     4. It has the function of detecting the disconnection of the thermocouple. If the disconnection of the thermocouple is detected, the channel value will be set to 30000. The disconnection status can also be queried for the sensor online status registers 1000110008.

     5. Correspondence between measuring temperature range of thermocouple and specific data

1. 1. Platinum resistance input

      1. All channels can be directly connected to the thermal resistance input, and can be connected to 2-wire and 3-wire temperature sensors, and the collected results are directly converted into actual temperature values.

      2. 4 types of thermal resistances, such as PT100, PT1000, CU50, CU100, can be selected, and the corresponding channel is set to the corresponding thermocouple type when in use.

      3. The temperature data result is a 16-bit signed int type, and the actual temperature is the actual temperature after dividing the read data by 10.

      4. It has the function of detecting the disconnection of the thermocouple. If the disconnection of the thermocouple is detected, the channel value will be set to -10000 or 30000. The disconnection status can also be queried in the sensor online status registers 1000110008.

      5. Correspondence between the measuring temperature range of thermal resistance and specific data

1. 1. Current input

      1. All channels can be directly connected to ±20mA, 4-20mA current input, and the collected results are directly converted into actual current values. Please insert the jumper caps of the corresponding channels on the internal circuit board of the module when using.

      2. ±20mA and 4-20mA current signals can be selected, and the corresponding channel is set to the corresponding current type when in use.

      3. The current data result is a 16-bit signed int type, and the actual current is the actual current after the read data is divided by 1000.

      4. 4-20mAThe input has the function of detecting the disconnection of the thermocouple. When the input current is lower than 2mA, it is judged that the bit is disconnected. The disconnection status can be queried in the sensor online status register 1000110008.

      5. Correspondence between current measurement temperature range and specific data

1. 1. Voltage input

      1. All channels can be directly connected to ±15mV, ±100mV, ±1V voltage input, and the collected results are directly converted into actual voltage values.

      2. The current signals of ±15mV, ±100mV and ±1V can be selected, and the corresponding channel is set to the corresponding voltage type when in use.

      3. The voltage data result is a 16-bit signed int type, and the data after reading passesThe following tableThe written magnification is calculated as the actual voltage.

      4. Correspondence between voltage measurement range and specific data

• Principle block diagram