Low Cost Analog to RS485 Multi-Input Common Ground Bus Smart Sensor Module: SY AD 04/SY AD08 Series
SunYuan SY series AD products (Adam module) can realize safe signal isolation and high-precision data acquisition, isolation conversion, monitoring and transmission between sensor and host. The products are widely used in RS-232/485 bus industrial automation control system, 4-20mA / 0-10V analog detection, monitoring and control, small signal measurement and industrial field sensor signal isolation transmission and other remote monitoring occasions. Through the configuration of the software, it can be accessed to a variety of sensor types, including current output type, voltage output type and so on.
The product internally includes modules for power isolation, signal isolation, linearization, A/D conversion and RS-485 serial communication. Each serial port can be connected to a maximum of 256 SY AD series modules, the communication method adopts ASCII code character communication protocol or MODBUS RTU communication protocol, and its instruction set is compatible with ADAM module, the baud rate can be set by the user, and it can be hooked up with the control modules of other manufacturers on the same RS-485 bus, which is convenient for programming by the host.
SY series AD products are intelligent monitoring and control system based on microcontroller, all the configuration information such as calibration value, address, baud rate, data format, calibration and status set by the user are stored in non-volatile memory EEPROM.
SY series AD products are designed and manufactured according to industrial standards, signal input/output isolation, can withstand 3000VDC isolation voltage, strong anti-interference ability, high reliability. Operating temperature range - 45℃～+80℃.
Multi-channel Analog Signal Acquisition Control Isolation Transmitter Function Introduction
SYAD02/4A signal isolation acquisition module can be used to measure two (or four) current or voltage signals that can be common ground and will not interfere with each other. Analog signal input: 24-bit acquisition accuracy, all signal input ranges have been fully calibrated before the product leaves the factory. In use, the user can also easily program their own calibration. For specific current or voltage input ranges, please refer to the product selection, and when measuring two signals, both input selections must be the same.
1、Communication protocol
Communication interface: 1 channel standard RS-485 communication interface and 1 channel standard RS-232 communication interface.
Communication protocol: Support two protocols, ASCII character protocol and MODBUS RTU communication protocol. It can be programmed to use that kind of communication protocol, which can realize network communication with many brands of PLC, RTU or computer monitoring system.
Data format: 10 bits, 1 start bit, 8 data bits, 1 stop bit.
Communication address: (00H-FFH) and baud rate (300, 600, 1200, 2400, 4800, 9600, 19200, 38400bps) can be set; the longest distance of the communication network can be up to 1200 meters, connected by twisted shielded cable. Communication interface high anti-interference design, ±15KV ESD protection, communication response time less than 100mS.
2、Anti-interference
The calibration sum can be set as required. Transient suppression diodes inside the module can effectively suppress various surge pulses and protect the module, and the internal digital filtering can also well suppress the industrial frequency interference from the power grid.
General Parameters
(typical @ +25℃, Vs is 24VDC)
Input type: Current input / Voltage input
Accuracy: 0.05%
Input misalignment: ±0.1 uA/°C
Temperature Drift: ±15 ppm/°C (±30 ppm/°C, max)
Input resistance: 50Ω (4-20mA/0-20mA/0-±20mA current input)
100Ω (0-10mA/0-±10mA current input)
1KΩ (0-1mA/0-±1mA current input)
Greater than 1MΩ (voltage input)
Input protection: Over-voltage protection, over-current protection
Bandwidth: -3 dB 10 Hz
Conversion rate: 10 Sps
Common Mode Rejection (CMR): 120 dB (1kΩ Source Imbalance @ 50/60 Hz)
Normal Mode Rejection (NMR): 60 dB (1kΩ Source Imbalance @ 50/60 Hz)
Communication: Protocols RS-485 or RS-232 ASCII character protocol and MODBUS RTU communication protocols
Baud rate (300, 600, 1200, 2400, 4800, 9600, 19200, 38400bps) is software configurable.
Address (00H~FFH) can be configured by software.
Communication response time: 100 ms max
Power supply: +8 - 50 VDC wide power supply range, internal anti-reverse connection and over-voltage protection circuitry
Power consumption: less than 1W
Operating temperature: - 45 - +80°C
Operating humidity: 10 - 90% (no condensation)
Storage temperature: - 55 - +85°C
Storage Humidity: 10 - 95% (no condensation)
Isolation Withstanding Voltage: Between Input/Output: 3KVDC, 1 minute, Leakage Current 1mA
Where output and power supply are common ground.
Surge Voltage: 3KVAC, 1.2/50us (peak)
Dimensions: 123 x 70 x 30 (mm)
Initializing the SYAD02/4A Module
When connecting to an RS-232/RS-485 network, the SYAD02/4A module must be assigned a unique address code, which is a hexadecimal number that takes values between 0x00 and 0xFF. All new SYAD02/4A modules use the same factory initial settings as shown below:
Address code 01H
Baud rate 9600 bps
Checksum disabled
ASCII character communication protocol
Since the new modules all have the same address code, their addresses will contradict the other modules, so when you set up your system you will have to reconfigure each module's address. You can modify the address of the SYAD02/4A module through the configuration commands after connecting the SYAD02/4A module power cable and RS485 communication cable. The baud rate, checksum status, and communication protocol also need to be adjusted according to the user's requirements. Before modifying the baud rate, checksum status and communication protocol, the module must be put into the configuration state first, otherwise it cannot be modified.
How to let the module enter the configuration state
SYAD02/4A modules have a special pin labeled CONFIG. Short the CONFIG pin to ground (GND pin), and then turn on the power, then the module enters the configuration state. In this state, the module is configured as follows:
Address code 00H
Baud rate 9600 bps
Prohibit checksum
ASCII character communication protocol
At this point, parameters such as baud rate, parity and status of the SYAD02/4A module can be modified by configuration commands, and the communication protocol can also be selected by the Set Module Communication Protocol command. When you are not sure about the specific configuration of a module, you can also install a configuration jumper to make the module enter the configuration state and then reconfigure the module. If the user needs to set the module to MODBUS RTU communication protocol, please see the relevant instructions in the MODBUS communication protocol chapter.
Module Calibration
Calibration must be done under ASCII character communication protocol. calibration is not supported under Modbus protocol.
The product has been calibrated at the factory and can be used directly without calibration. Users can also recalibrate the module during use. During calibration, the module needs to be inputted with appropriate signals, and different input ranges require different input signals.
In order to improve the calibration accuracy, it is recommended to use the following equipment for calibration:
1, a DC voltage/current signal source with a stable output and very low noise level
2, a 5 ½ digit or higher precision voltage/current measuring instrument to monitor the accuracy of the input signal
Calibration process
1. Select the input channel to be calibrated and connect the corresponding input signal according to the input range of the module.
2. The zero point of SYAD02/4A module is calibrated at input 0, and the fullness is calibrated at 120% of the input fullness. For example, for 4-20mA input, input 0mA when calibrating the zero point, and input 24mA when calibrating the fullness. (For 0-5V input, input 0V when calibrating the zero point, and input 6V when calibrating the fullness).
3. Input the zero signal, usually 0mA or 0V, to the channel of the analog input module to be calibrated.
4. After the signal is stabilized, send the offset calibration $AA1N command to the analog input module (N stands for the code of the channel currently being calibrated, 0 or 1).
5. Input a current or voltage signal at 120% of full scale to the channel to be calibrated by the analog input module.
6. After the signal is stabilized, send the gain calibration $AA0N command to the analog input module (N represents the channel code of the channel currently being calibrated, 0 or 1).
7. Calibration completed
