Condition:New
Type:Logic ICs
Summary
DAS-RTD16 is a 16-channel pt100 temperature acquisition module, which directly connects 16 pt100 temperature components, collects 16 channels of temperature, and directly converts them into temperature values. It adopts RS485 communication interface and supports MODBUS-RTU protocol. It can connect PLC, DCS and various configuration softwares at home and abroad (Kingview, MCGS, etc.).
The module is designed according to strict industrial standards. The input channel uses a 400V-tolerant switching device, which uses three-wire dual-ended differential input, ΔΣAD conversion, digital filtering, electrical isolation, power reverse connection protection, disconnection detection, triple watchdog, etc. Technology with strong anti-interference performance and high reliability。
Technical indicators
● Number of channels: 16 pt100 RTD inputs.
● Measurement range: -100 ° C ~ 500 ° C.
● Accuracy: ±0.3 °C.
● Scanning period: 1 second.
● Resolution: 20 AD.
● Isolation voltage: 1500V network isolation; 400V isolation between channels.
● Communication interface: RS485/MODBUS-RTU protocol.
● Communication distance: 1200 meters, ordinary twisted pair
● Dimensions: 146X90X42mm, rail mounted.
● Working power: 24VDC / 1W.
●Working environment: temperature -20 ~ 70 ° C, humidity ≤ 85% RH
Network communication
The degree module uses the standard RS485 network wiring method, as shown below. The communication cable uses shielded twisted pair cable. Each end of the network uses a 220Ω matching resistor. Up to 16 temperature modules can be connected, and the maximum length is 1200 meters. The temperature module adopts MODBUS-RTU communication protocol and RS485 communication interface. The host software meets the following five elements to realize communication with the temperature module: ● Use the 03 function code of MODBUS-RTU protocol; ● Clear the address of the temperature module (1~16); ● The corresponding register number of the temperature module 1~16 channel is 1~16; ● The temperature module upload data format is double-byte 16-bit signed integer; ● The communication baud rate and communication format are consistent with the temperature module (9600/19200 optional) , 1 start bit, 8 data bits, 1 stop bit, no parity bit).
The communication process of the MODBUS-RTU protocol for the host to read the data collected from 1 to 16 channels using the 03 function code to the temperature module of the 01 address is as follows:
Host send string: 01H 03H 00H 00H 00H 10H CRC CRC
Module reply string: 01H 03H 20H Data 1 Data 2 Data 3... Data 16 CRC CRC
Note 1: 01H and 03H of the transmission string are the address number and function code respectively, 00H 00H is the start register address (1 channel), 00H 10H means 16 registers, and 20H of the reply string indicates that the following data has 32 words. Section (16 channel data), data 1 to data 16 are 16 channels of data, each data is a double-byte signed integer, a total of 32 bytes. The CRC is a 16-bit CRC.
Note 2: The temperature module returns the data 1 to 16 of the host to the data obtained by expanding the temperature collection result of each channel by 10 times and then taking the integer. The host will reduce the data read by 10 to the original temperature, thus retaining 1 decimal place with a temperature resolution of 0.1 °C.
Note 3: The MODBUS-RTU protocol is embedded in the PLC, DCS, and various configuration software. As long as the temperature module address, register address, function code, baud rate, and data format are known, MODBUS-RTU communication can be realized. You don't need to analyze the content of the protocol yourself. Here is just a demonstration of the communication process. The company has no right or ability to explain the content of the agreement. If there is a need for the content of the agreement, please find the authoritative protocol specification.
Module settings
D The AS module is factory set to: 9600 baud rate, address 1. If you need to change, open the module, the internal S1 jumper sets the baud rate (9600/19200), and the S2 combination jumper sets the address (1~16). See the table below for the setting method.
Instructions
The terminal arrangement of the DAS-RTD16 module is shown below.
The “RUN” of the DAS-RTD16 module is the running light, which flashes at 1 second during normal operation; “COM” is the communication light, and each communication flashes once.
P+, P-, G: 24VDC power supply terminal, P+ terminal is positive, P- is negative, and G is ground terminal. The G terminal must be connected to the ground reliably to effectively suppress interference.
A+, B-, S: RS485 terminals, A+, B- are connected to A+ and B- of RS485 network by twisted pair. S connects the shield of the twisted pair and eventually connects to the ground.
A, B, C: A, B are channel input terminals, C is the common end of the input channel, a total of 16 input channels.
The pt100 thermal resistor uses a three-wire input method to automatically eliminate lead resistance errors. The wiring is shown above. C is the common end of 16 input channels, there are 4 C terminals, and the common end of pt100 of 16 channels is connected to the C terminal.
The module directly converts the collected results into temperature values, and the result is 10 times the actual temperature. For example, if the data read by a communication host is 265, the actual temperature is 26.5 °C.
When there is a line break in the pt100 input, the channel's acquisition result is “32767”, indicating that the channel input signal is disconnected or the acquisition temperature is out of range.
The ground terminal "G" of the module must be connected to the ground reliably, otherwise it will interfere with the acquisition result.
Shielded wires must be used for the input signal cable, and the shielded wires must be grounded.
