Domestic PLC—IKON Drive PLC expansion module for remote IO use introduction
Author: Xiamen IKON Drive Technical Support Department
With the continuous development of industrial technology, the remote IO function of the expansion module has become increasingly prominent, and its role is evident. It is extremely important for a system that needs to collect and monitor a large number of scattered switching or analog signals (temperature, humidity, differential pressure, air volume, flow rate, fan speed, valve opening, etc.), which can easily realize distributed installation control and can The expansion of unlimited points greatly improves the configuration flexibility of the control system and the control expansion capability in the future, reduces the wiring amount of various signals, and also reduces the interference problem caused by the long analog signal line. Save engineering investment costs.
IKON Drive expansion module comes with an RS485 communication port, supports Modbus protocol, and can be used as a Modbus slave station. in:
Address : 1-254 can be set
Baud rate : 2400, 4800, 9600, 19200, 38400, 57600, 115200 optional.
Data formats : N, 8, 2 RTU, E, 8, 1 RTU, O, 8, 1 RTU, N, 8, 1 RTU
E, 7, 1 ASCII, O, 7, 1 ASCII, N, 7, 2 ASCII are optional.
1. Except for the 8-point switch module and the H04DT module, all other modules have an RS485 communication port.
2. 16-point switch module, 4-point analog module and temperature module without DIP switch. The DIP switch on the module is used to set the address. If the module has an external DIP switch, the address set by the switch shall prevail (the address range that can be set by the 4-bit DIP switch is 1~15); if the module does not have a DIP switch The address set by the programming software shall prevail.
3. How to set the address, baud rate and data format of the module through programming software? the following:
3.1 Hardware connection: Since the module has an RS485 communication interface, the computer with a serial port can use 232 to 485 to connect to the module; if it is a USB interface, it can use USB to 485 to connect to the module.
3.2 Software operation:
1. Click the tool on the menu bar of the programming software – “Remote Module”, click the button in the pop-up window , and open “Online”
window. The default address of the module is 1, 19200, N 8 2 RTU, and the connection is successful as shown in the following figure:
Click Exit to enter the Remote Module window.
In the window of the remote module, the address, baud rate, data format and filter time of the module can be modified on the right. As shown below:
After modifying the communication parameters you want, click the parameters to download. Under normal circumstances, the default 19200N 8 2 can be used without modification. Let’s look at some test examples.
Since the module uses the Modbus protocol, the CR number in the table below is the corresponding Modbus address.
From the above table it can be seen that:
10H-4FH is the input value of DI channel 1-64;
50H-8FH is the output value of DO channel 1-64 channel.
This is key information! That is to say, we can know the actual state of IO as long as we read the Modbus address corresponding to the input and output on the host computer.
The following example:
Application example 1 : The switch module H16XDR is used for remote IO
Requirement: The host reads the status of the input points X0-X7 of the remote IO module H16XDR module through communication, and controls the output points Y0-Y7. The procedure to read the status of H16XDR input points X0-X7 is as follows:
In the user program, M0 is the input point X0 on the module, and so on.
The program to write the status of H16XDR output points Y0-Y7 is as follows:
After downloading the program to the PLC, click online monitoring, and writing M0-M7 is to write the status of Y0-Y7. The online monitoring is as follows:
The read and write IO status program of the above H16XDR module is the same as that of other switch modules with communication ports.
Application example 2 : Analog module S04AO used for remote IO
The address, baud rate, and data format of the analog module are the same as those described above. The address of the module in this example is 2 baud rate 19200 data format N 8 2RTU. Like the switch module, we must also know the Modbus address corresponding to each channel of the analog quantity. For detailed information, you can go to the online help of Haiwell programming software – check . The following is the information corresponding to some Modbus addresses related to S04AO.
As can be seen from the above figure, the Modbus corresponding to the analog output channels AQ0-AQ3 is 10H-13H, so when writing the communication program in the PLC, you only need to write values to the 4 consecutive channels. The procedure is as follows:
Similarly, other analog modules, thermal resistance, thermocouple read and write methods are the same as this example. For example, the program to read the 8-channel temperature value of H08TC can be written as follows, the module address is 3 baud rate 19200 data format N 8 2RTU.
Application Example 3 : Digital temperature module H32DT used as remote IO
The address, baud rate, and data format of the analog module are the same as those described above. The address of the module in this example is 4 baud rate 19200 data format N 8 2RTU.
As can be seen from the above figure, the Modbus corresponding to channel 1 and channel 2 are 10H-1FH and 20H-2FH, each with 16 channel values, so write the communication program in the PLC as follows:
Summary: IKON Drive full series of PLC CPU hosts have 2 communication ports (RS232+RS485), which can be expanded to 5 communication ports. Each communication port can be programmed and networked, and can be used as a master station or a slave station. It supports 1:N, N:1, N:N networking mode, supports various man-machine interfaces and configuration software, and can be networked with any third-party device with communication function (frequency converter, instrument, bar code reader, etc.).
Therefore, multiple remote IO modules can be connected to each communication port, which greatly improves the expansion capability of PLC IO points, is flexible and convenient, and plays an increasingly important role in the field of industrial control automation.
IKON Drive official website: https://www.ikondrives.com/
Programming software download address: HaiwellHappy
1. Physical connection diagram of module and programming software:
2. The connection diagram of PLC and module for remote IO physical object:
3. With the host computer such as configuration software, touch screen, text or PLC, as long as the Modbus protocol is selected, the data of the module can be collected and monitored.