CAN bus and the man-machine interface in the tunnel kiln control system application

Huangshi coldwell control co. , LTD xiao-peng deng, liu guan, YouHu abstract: using CAN bus technology form is given priority to with embedded PLC station CAN network, using PID algorithm, combined with industrial man-machine interface, implementation of tunnel kiln system logic control and process control. Key words: tunnel kiln, CAN bus, the embedded PLC, PID, man-machine interface 1 introduction is a kind of continuous kiln, tunnel kiln is mainly used for ceramic building materials, ceramics for daily use, such as fire, in terms of its structure is mainly composed of preheating zone, high temperature, quench zone mild cold zone, involving the fan control, the control of tunnel kiln temperature testing, pressure testing, temperature control, pressure control and other control. The CAN bus technology in the tunnel kiln control system, CAN well meet the requirements of real-time temperature and pressure control, system communication rate is high, the stability is strong, and the participation of industrial-grade man-machine interface, make the control system is more intuitive, easy to use and operate. Below a ceramics factory in hebei tangshan a tunnel kiln as a case, the implementation process of the control system is introduced in this paper. 2 control object of the kiln is a 80 m long gas tunnel kiln, a total of temperature testing point 20 ( Dividing 12 K, S dividing 8) , of which 10 point temperature control, pressure testing point 2, 10 actuators, gas burner flame detection, only 10 fan: exhaust fan (2) ( Use a prepare) Two combustion fan ( Use a prepare) 2, rapid cooling fan ( Use a prepare) 2, slow cooling fan ( Use a prepare) 2, suction fan, Use a prepare) Curtain, kiln head kiln exhaust fan each one. 10 PM temperature control is through the size of the valve position control actuators, change how much fuel injection, making the temperature stability. 2 point pressure control by adjusting the smoke exhaust fan and rapid cooling fan speed control, namely by adjusting the smoke exhaust and quench frequency inverter to control the pressure. In addition to fan chain, burner flameout alarm and all kinds of fault alarm. 3 kiln control system the composition of the control system consists of three embedded PLC ( 简单— M2416R) , 2 sets CAN - AD1216, one CAN AD1208, one CAN DA1208 etc parts. Among them, the embedded PLC to control the logic of switch quantity, PID algorithm, and through CAN bus and at a lower level of communication module; Temperature acquisition module CAN - AD1216 20 point temperature simulation used to complete the acquisition; Pressure acquisition module CAN - AD1208 to sample 2 point pressure signal; Analog output module CAN - DA1208 is used to control the fan frequency converter. For the system under the frame: embedded PLC as the control core of this system Easy - AD1216, lower network using CAN bus to communicate, to respectively RS0 mouth and HMI ( Human machine interface) , RS1 mouth to communicate with the computer. Its characteristics are as follows: 3. 1 there is a powerful communication function: all the CAN bus interface standard planning in the application layer, the CAN bus that follow the standard equipment, CAN be set by CANSET software CAN network configuration file, download the curing to EASY - M2416R, CAN put the equipment is mapped to the CAN network. The CAN bus has good real-time performance, reliability and anti-interference ability, and error detection ability, so in some conditions are widely used in a tough situation. RS0 in addition, a serial port can be used to monitor the ladder diagram program and the upper machine, can also with man-machine interface communication; Serial port RS1 CAN be used to download CANSET CAN network configuration file generated by the software, you CAN also through the RS485 network connection to a third party equipment, such as PC, mitsubishi PLC. Due to each network are independent, with a network of PLC in the connect to multiple patterns are not affected. 3. 2 and mitsubishi considerable computational speed and almost fully compatible with the development of the environment: after test, basic instruction operation speed in 0. Step 5 u/below, and mitsubishi FX2 series PLC, this for users to control requirements is not very tall is enough. The ladder diagram and instruction and mitsubishi PLC is also fully compatible with, and can be a good run in the mitsubishi programming software. Used for the mitsubishi PLC users to reduce a lot of difficulties. 3. Three independent development of CAN bus connected CANSET software: CANSET software CAN complete the communication Settings very easily. Setting include: the total number of network equipment, network equipment address, the content of the network communication data, the network data communication speed, etc. It can also according to user needs, set the task of each device level, to ensure the reasonable allocation of network resources. In the lower network AD and DA, and Easy M2416R equipment, follow the CANBUS protocol interface, CAN be easily connected to CAN bus network, become a part of the system. 4 the realization of the function of system 4. 1 all the logical control and PID control are made Easy - M2416R completed, the CAN bus network in three PLC in choose one as the master station, choose Easy - here M2416R - 1 as the master station. It through CAN bus communication with each device for the bottom of the network, the communication between two devices must also be accomplished by the host. At the same time it as from station with PC ( PC) And HMI ( Human machine interface) To communicate. 4. 2 the CAN bus network interconnection also to CANSET software implementation, it is a graphical interface of the software, set up is very simple, and in addition to the address in the PLC ladder diagram and master-slave station without having to set to other relevant content, to some extent, simplifies the programming workload. Below is set up under the CANSET this system CAN network configuration: