The Application of Siemens PLC 300 in Crane
Crane is a general name of the driving, cranes and cranes , according to its function is generally divided into three categories: one, light duty overhead crane, two, heavy duty overhead crane, three, jib crane. This article refers to the double girder overhead crane, we tentatively called the traffic. With the continuous improvement of the degree of automation, PLC in the traffic in the application of more and more. The author of the company used in the field of metallurgy is the need to achieve high-precision positioning of the traffic, you can achieve manual / semi-automatic operation, the positioning error requirements within 10mm.
- System composition
The traffic by the Siemens PLC300, ABB inverter, Dijia Fu WCS series coding and positioning system and so on.
Siemens PLC as the core of the entire control, through the encoder as its tactile senses, with PROFIBUS communication as the central part of the contact, drive the ABB inverter and control the electrical components control driving carts, cars, hanger and other parts of the work.
1.1 hardware components
PLC part of the selection CPU317-2DP, signal processing module CP343-1 and some input and output digital, analog modules; drive selection ABB drive; positioning system sub-car cart positioning and the main winch positioning two parts, respectively, the use of P + F encoder and HENGSTLER encoder; control is divided into touch screen MP370 and console handle two parts. PLC uses the Internet network and touch screen communication, through the PROFISBUS-DP connection frequency changer, the encoder. The communication distance is extended by the use of repeaters in the middle due to the distance of part of the components. Internet network using a five HUB, you can connect PC and PLC, but also for traffic and other equipment to do the bedding.
1.2 Software configuration
PLC design using STEP 7, control screen design using WINCC FLEXIBLE 2005.
1.3 Principles of programming
The coding belt used for the positioning of the cart is fixed on the side of the plant, and the code is used to encode the girders that are fixed between the two beams of the carriage. The two use the P + F reading terminal WCS2A-LS221 to read the data from the coding tape, To the interface module WCS-PG210, through the WCS-PG210 data processing, through the PROFIBUS-DP to the PLC. Driving the main hoist Use the HENGSTLER encoder AC58 / 1212EK.42DPZ to set and read the height of the main winch, and transfer the data to the PLC via the PROFIBUS-DP interface of the encoder itself. During the installation and commissioning of the vehicle, the corresponding working groove surface is designed according to the scene in the working area on the control screen. Then, each working groove surface of the working area is positioned by manual positioning. The position of the working slot and The height of the main winch is input to the PLC. When the operator is operating, simply select the slot on the operation screen to select the button from the manual to the semi-automatic position, step on the pedal controller can be semi-automatic operation.
This type of traffic for the need for high-precision positioning of the working environment, from the cost and maintenance costs are more expensive, the need for operators to operate, can only achieve semi-automatic operation, to achieve full automatic operation also need some improvement.