Analysis of loom monitoring system in the most cot

Cotton mill loom monitoring system analysis paper

1 system introduction

1.1 system function

a cotton mill loom monitoring system, through the cooperation of lower computer, central monitoring controller and operator workstation, 28 × The running conditions of 14 looms are monitored in real time. The design objective requires that the weaving length of a single loom in each shift can be counted in real time, the total cloth length of each group and each type of weaving can be calculated and displayed on the large screen of the workshop, and the working condition alarm can be given to the machine with too low speed or abnormally high speed, so that the management personnel can timely notify the maintenance personnel for maintenance. Record efficient machines and weaving teams and give rewards. At the same time, the total weaving output of each team, daily and monthly shall be counted according to the recorded data

1.2 system structure

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1.2.1 the lower monitoring computer

system makes the reed tube suck in and generate level pulse through the rotation of the machine wheel installed on the loom. The lower monitoring computer is responsible for counting the level pulses of 14 looms because the medical devices containing PVC will release harmful chemicals during routine use and waste treatment. The weaving output of the loom can be calculated by the following formula:

l=c × K × (1-r)

in the formula, L - the actual weaving output, C - the number of pulses, K - the cloth length coefficient (the weaving length that produces a pulse), R - the shrinkage of the variety. The lower machine also counts the startup and shutdown times of each loom, and judges the operation status of the loom for the central control computer to query. The lower monitoring computer is composed of MCS-51 single chip microcomputer and has standard RS485 interface to communicate with the central control computer. Nonvolatile memory NVRAM is equipped on the board to ensure that real-time data will not be lost after power failure

1.2.2 central monitoring computer

the central monitoring computer is served by the embedded Ethernet controller 7188E, which is responsible for reading the working data of each machine from the lower computer, and displaying the output of each group on the large screen after grouping statistics. At the end of each weaving shift (2:00, 10:00, 18:00), self leveling and pressing three times will store the production data of the shift into the flash EPROM memory on board for the operator station to read, and at the same time, send a clear command to the lower computer to start the collection of weaving data of the new shift

1.2.3 operator station

the operator station is composed of an ordinary PC computer or an industrial control computer, which is responsible for reading the historical data of each team of the central monitoring computer and storing it in the database. It can not only display the output of each team and variety at present, but also display the current operation status of each loom in real time. You can also call historical data summary to generate various reports and submit them to the superior management department

1.2.4 data communication mode

due to the long distance between the central control computer and the lower computer, the data transmission between them adopts RS485 industrial control bus. The 7188E and the operator station are connected by standard 10Mbps Ethernet

2. Application of Embedded Ethernet control module 7188E

2.1 introduction to 7188E functions

embedded Ethernet controller ICP Das 7188E contains an AMD 80188 CPU with a main frequency of 40MHz, 256Kb SRAM as the data memory, and 256 KB flash is mostly EPROM caused by the drying of gauze on the wet ball sensor as the program memory. The module is equipped with an RJ-45 connector for local area connection An i/o expansion bus, a standard RS485 bus interface and an RS232 interface are used for writing firmware programs and setting parameters

a DOS like operating system minios 7 is built into the 7188E controller, and users develop their own programs to run in this environment. Compared with DOS or other industrial computer operating systems, minios 7 has the characteristics of small size, fast speed and low price. Its biggest advantage is its fast startup speed. The startup time of embedded control modules based on romdos operating system on the market is about a few seconds, while the loading time of minios 7 is only 100ms. With the startup time of user applications, the control program can be restarted within 1 second, 7188E itself has a 1.6 second watchdog circuit, so 7188E not only has the characteristics of PLC fast and stable, but also has the powerful communication and control calculation function of industrial computer, which is the perfect combination of PLC and industrial computer

7188e series controllers have three typical applications (virtual serial port, Ethernet i/o, web server). These applications use different hardware and different types of programs. Users can choose any application they like. When selecting virtual serial port application, a PC can control 256 serial ports (including real COM ports). Vxcomm hardware can turn the 7188E module into an RS-232 to Ethernet/Internet converter. Using Ethernet i/o and network server, users can program the hardware (xserver) of 7188E

2.2 description

as mentioned above, the 7188E has three application modes: virtual serial port, Ethernet i/o, and web server. In the loom monitoring system, the 7188E uses xserver (i.e. web server) mode to work. Xserver is a package written by the developers of 7188E. It is an application that can run completely, including tcp/ip support for 10baset Ethernet. Although it does not have a clear main function entry, it provides several function entries for users to connect their own code, such as:

void userloopfun (void)

xserver works in a way similar to PLC cycle scanning, and this function will be called during each cycle. The 7188E comes with a real-time clock (RTC) that can be accurate to 1 millisecond. Users call the installusertimer function to set their own timer overflow time and entry function. In this example, set a count value in the entry function. Every time you run to userloopfun to query the count value, if the collection time (0.5 seconds) is exceeded, enter the program above to run the data collection program

the program in the central control computer 7188E is written in C or c++ under the Borland c++ 3.1 development environment. After successful debugging, it is downloaded to the flash EPROM by the 7188E through the data line

2.3 RS485 communication connection

7188e is connected with the lower computer by industrial control bus RS485, and 7188E is read from the lower computer by polling. 7188E sends two commands to each lower machine: Command 1 reads the weaving pulse number and loom status of 14 looms; Command 2 reads the startup time and shutdown time of 14 looms, and the program realizes the conversion of sending different commands through state conversion

because 1. Variable frequency system tensile testing machine: adopt variable frequency motor control system RS485, which is a single duplex serial communication party