VMMORE has launched an innovative product that integrates temperature controller and PLC functions. It can be used as a standalone 8-channel temperature controller while also integrating all the functions of the PC2MU series PLC. This article introduces four application methods based on the features of the multi-channel programmable temperature controller.
Table of contents
1. Hardware and software resources for multi-channel programmable temperature controller
1.1 Hardware Configuration Resources
1.2 Software Configuration Resources
2. Application Introduction of Multi-channel Programmable Temperature Controller
2.1 A multi-channel programmable temperature controller is used for temperature control, with a PLC controlling two controllers.
2.2 The multi-channel programmable temperature controller is directly connected to the touch screen.
2.3 The multi-channel programmable temperature controller and the touch screen are connected in a one-screen-multiple-devices manner.
2.4 The multi-channel programmable temperature controller communicates with the PLC as a Modbus slave.
1. Hardware and software resources for multi-channel programmable temperature controller
1.1 Hardware Configuration Resources
1.1.1 The multi-channel programmable temperature controller integrates 8 temperature measurement input channels, supporting RTD and thermocouple inputs;
1.1.2 Four digital inputs, supporting high-speed counting function, with a maximum counting frequency of 60KHz;
1.1.3 10 digital outputs, including 2 high-speed digital outputs supporting 100KHz high-speed pulse output; the other 8 digital outputs are used to control solid-state relay heating or for PLC logic functions;
1.1.4 Integrated with 3 communication ports: one 422 programming port, supporting programming port protocol and Modbus slave protocol, with a communication rate of up to 115K; one 485 communication port, supporting programming port protocol, Modbus master-slave protocol, RS4851:N protocol, with a rate of up to 115K; and one CAN port, supporting CANBUS protocol, with a rate of up to 1M.
1.2 Software Configuration Resources
1.2.1 The multi-channel programmable temperature controller supports all instructions and software components of the PC2MU;
1.2.2 When using the temperature control function, the temperature control-related parameters are directly mapped to the R and M elements of the multi-channel programmable temperature controller (please refer to the manual for specific mapping relationships). The settings can be directly displayed on the touch screen, achieving up to 40 temperature control channels without programming.
2. Application Introduction of Multi-channel Programmable Temperature Controller
2.1 A multi-channel programmable temperature controller is used for temperature control, with a PLC controlling two controllers.
This multi-channel programmable temperature controller integrates 8-channel temperature control and also incorporates all the PLC functions of the PC2MU. Therefore, it can function as both a temperature controller and a PLC master unit to run control programs.
Temperature control introduction of multi-channel programmable temperature controller:
The first step is to open the Epro software and create a new project. There are two types of multi-channel programmable temperature controllers: PC2MU-PT08 and PC2MU-TC08. This example uses PC2MU-PT08.
The second step is to click on the thermostat parameters -> temperature control settings -> host output point settings in the engineering tree list on the left, and assign one Y output to each channel for heating control; download the thermostat parameters to the module, and they will take effect after powering on again;
The third step is to set and debug the temperature control parameters. Double-click the temperature controller main unit in the project tree list. In the pop-up debugging screen, set the relevant temperature control parameters and enable temperature control and temperature PID self-tuning. After debugging, click "Write Settings" to save the relevant parameters to the module.
The programming instructions for multi-channel programmable temperature controllers are as follows:
The first step is to open the Epro software and create a new project. There are two types of multi-channel programmable temperature controllers: PC2MU-PT08 and PC2MU-TC08. This example uses PC2MU-PT08.
The second step is to input the ladder diagram control program in the program editing interface.
Third step, click the download icon or select online -> thermostat writing.
Fourth step, select the program, click execute, and download it to the multi-channel programmable temperature controller.
2.2 The multi-channel programmable temperature controller is directly connected to the touch screen.
Chapter 1 introduces that both COM0 (programming port) and COM1 (485 port) of the multi-channel programmable controller support programming port protocols. If the touch screen has two communication ports, it can connect to two slave devices simultaneously. One communication port of the touch screen can be connected to the PLC; the other communication port, using the programming port protocol, can be connected to the multi-channel programmable temperature controller.
Taking a Hitech touchscreen as an example, as shown in the diagram above, the touchscreen's COM1 port is connected to a Siemens PLC, and COM2 is connected to a multi-channel temperature controller. The specific operation is as follows:
2.2.1 Open the Hitech editing software ADP, create a new project, and select Siemens S7-200 as the PLC type.
2.2.2 Click the "Connection" menu in the working parameters menu, select COM2 for communication port/connection method, select Add Connection, and set a device name in the pop-up settings box, such as PC2MU-TC08. Select the programming port protocol MitsubishiFX3UC for device type.
2.2.3 Example of setting temperature display and temperature setting components on the touch screen. For example, the temperature measurement value of channel one of a multi-channel temperature controller is mapped to R0, and the temperature setting value of channel one is mapped to R18. The operation of R0 value display is as follows: Place a value display component on the screen, double-click the value display component, and the value display setting box shown in the figure below will pop up; click the button shown in the red circle to set the variable; in the pop-up "Address/Constant Input", select 2-PC2MU-TC08 for the connection, select R for the component type, and fill in 0 for the address/value.
The operation of setting the value of R18 (channel one temperature setpoint mapping element) on the touch screen is as follows: Place a value input element on the screen and double-click the element; in the pop-up value input dialog box, click the button shown in red circle in the figure; in the pop-up "Address/Constant Input" window, select 2-PC2MU-TC08 for the connection, select R for the element type, and enter 18 for the address/value.
All R and M components can refer to the above steps. Note that the connection in the variable settings must be set to connection 2 (in this example, we set connection 2 to PC2MU-PT08).
2.3 The multi-channel programmable temperature controller and the touch screen are connected in a one-screen-multiple-devices manner.
If the user's touchscreen only has one communication port to connect to a lower-level machine, and the PLC used is a Mitsubishi FX2N or FX3U, then the FX2N or FX3UC multi-channel programmable temperature controller can be connected to the touchscreen simultaneously via RS-485, selecting RS-485ADP protocol. The FX2N and FX3UC main units do not have RS-485 communication ports, so an RS-485 communication expansion card is required. The connection is shown in the diagram below:
Taking the Weinview touchscreen as an example, this section explains how to connect both an FX2N and a multi-channel programmable temperature controller to a single communication port. The communication port settings for the FX2N host are configured in the PLC parameters and will not be detailed here. The following section details the settings for the multi-channel temperature controller.
2.3.1 First, set the COM1 port of the multi-channel programmable temperature controller to the SerialLink (RS4851:N) protocol.
First, open the programming software Epro, create a new project, select the multi-channel temperature controller type, and click OK;
The second step is to click on the temperature controller communication settings in the left-hand project tree, select COM1 configuration, and set the protocol of COM1 to seriallink (RS4851:N). Note that the station number here should be different from the station number of the Mitsubishi PLC; baud rate 19200, data bits 7 bits, stop bits 1 bit, even parity, control format select format 1, and select sum check.
Third step, click the download icon or select online -> thermostat writing;
Fourth step: In the pop-up download box, select thermostat communication settings, click execute, and download to the thermostat.
2.3.2 Setting up the Weinview screen editing software Easybuild8000. The specific steps are as follows:
First, create a new project. Open the system parameter settings box, click "Add", and in the pop-up device properties box, make the following settings: Set the location to the local machine; select MITSUBISHIFX232/485BD for PLC type and RS485-2W for interface type; set the PLC preset station number to 1; set COM to COM1 (19200, E, 7, 1); click "OK" and save the project.
The second step is to display the set temperature parameters on the touchscreen. All temperature control parameters in a multi-channel programmable temperature controller are mapped to R and M elements. The MITSUBISHIFX232/485BD in Easybuild8000 does not support R elements, only D elements. Therefore, it's necessary to use D elements to pass the parameters within the multi-channel programmable temperature controller. For example, to display the measured value R0 of channel one, you can first assign the value of R0 to D0 using the mov instruction, and then display the value of D0 on the touchscreen. Similarly, to set the target temperature value R18 for channel one, you can set D18 on the touchscreen and then assign D18 to R18 using the mov instruction.
To display the multi-channel temperature controller D0: Place a numerical display element on the screen, select device type D; enter 2#0 for the address, indicating that the displayed value is station number 2, D0.
To set up the multi-channel temperature controller D18: Place a numerical setting element on the screen, select device type D; set the address to 2#18, indicating that the element being set is D18 of station number 2.
2.4 The multi-channel programmable temperature controller communicates with the PLC as a Modbus slave.
Taking a Siemens PLC as an example, if the Siemens PLC has two communication ports (such as CPU226), the following solution can be adopted. One communication port of the Siemens PLC is connected to the host computer touch screen; the other communication port communicates with the multi-channel temperature controller via Modbus to read and set the temperature data of the multi-channel programmable temperature controller.
2.4.1 Set the COM1 of the multi-channel programmable temperature controller as a Modbus slave.
The first step is to open the Epro software and create a new project. There are two types of multi-channel temperature controllers: PC2MU-PT08 and PC2MU-TC08. This example uses PC2MU-PT08.
The second step is to click "OK". A project tree will pop up on the left side of the project. Double-click the thermostat communication settings in the image below;
Third, in the pop-up temperature controller communication settings box, select COM1 configuration, set COM1 station number to 1, RTU mode, baud rate 9600, data bits 8 bits, stop bits 1 bit, odd parity, and response delay 2ms. Click the OK button;
Step 4: Click the download icon or select Online -> Temperature Controller Writing;
2.4.2 Introduction to Modbus Master Communication with S7-200. For software versions V4.0STEP7MicroWINSP4 and above, the MBUS_CTRL and MBUS_MSG library files are required for S7-200 master communication.
The first step, MBUS_CTRL, is used to set the communication parameters of Port0 of the master PLC.
EN must be called every cycle, driven by SM0.0;
When Mode is 1, Port0 uses the Modbus protocol; when it is 0, the Modbus protocol is disabled.
Band and baud rate settings can be consistent with the slave settings; in the example, it is set to 9600.
Parity, the parity check method selection. 0 for no parity, 1 for odd parity, 2 for even parity; the example is set to odd parity.
Timeout, communication timeout period, in milliseconds, typical setting is 1000ms;
Done, keep it at 1;
Error, error code: 0 = no error, 1 = checksum error, 2 = baud rate error, 3 = timeout error, 4 = mode error;
The second step, MBUS_MSG, sets up read and write operations for the slave registers. Here, we will describe the read operation:
EN must be called every cycle, driven by SM0.0;
When First is 1, a single send request is generated, driven by the rising edge, and cannot be called consecutively.
Slave, the slave station number, is set to 1 in the example;
RW, read/write operation selection, 0 for read operation, 1 for write operation;
Addr reads the slave register address: 00xxx bit output (coil), 10xxx bit input (contact), 30xxx bit analog input register, 4xxxx holding register. In the example, it is set to 48513, which is the Modbus address of R0 of the slave multi-channel temperature controller.
Count, the number of registers read and written, is set to 8 in the example;
DataPtr, the storage address for reading and writing data, is set to &VB0 here. This means that the contents of the 8 registers starting from the slave Modbus address 8513 are read and stored in the 8 word elements starting from VW0.
