Study Of The Network Control System For CNC Lathes

With the developing of market economy and enterprise information, the amount of NC machines of enterprises is more and more. And managing mode of traditional single machine is not available for developing requests of the enterprises due to some abuses, such as backward technical measures, low productivity, costly managing and maintenance expenditures etc. "How to strengthen them to make them greatly bring into play in economical benefits" has been common demands of many enterprises, at the same time, also it is key projects of research and development of many manufacturers of NC machines and NC control systems.Directed against the practical conditions of difficult networking of the NC machines due to the fact that NC equipment used at present in the enterprises of our country is under many different NC systems and models, and different degree of the products, the paper raises that a project of combination of using PLC and RS232 interface for realizing network control of NC machines. In this project we can complete following items through monitoring PLC of the higher position and combining control of PLC of machine: the first, managing of turning time of the NC machines, that is, controlling of the turning times of the machines in every shift, when the times reach the specified schedule, the network system lockes the machines automatically; The second, monitoring the change of the signal input of the machines measured by PLC, accumulating the effective work times, displaying the state of the current machine turning on the touch screen (such as machine alarming, the state under working and the sate of non-working of the machine, etc.) and the state of the machine working (such as the effective machining times, the quantities of turned workpieces of current, etc.). The third, administrator can lock the machine to force the operator to maintain the machine according to the maintenance requirements of the machine. And the last one, using the PLC and RS232 interface, the active computer can send and receive the machining process of workpiece to/from the designated NC machine, centralize to manage the turning programs in workshop, and distribute production tasks and print the task lists, make statistics of drawing tool inserts as well asmaintain the NC machines of the workshop by using the managing program developed for the workshop.The network control technique of NC lathes realized by the paper is characterized by good common use and low in cost, so it may apply to NC lathes which can be provided with many kinds of NC control systems, for example, NC control systems of FANUC, SIEMENS, MITSUBISHI, and it can realize the effective collective monitoring and managing of NC machines working in situ and computer auxiliaryly manages turning programs of workshop and machining tasks of sections, and make a stability foundation for the basic schema of the CIMS for modern enterprises.