Data Transfer Methods of Cnc
Author: Gargi Nath
A CNC machine cannot function without a program. And a program cannot make its way to the machine without an effective data transfer system. So, what are the methods of data transfer and how effective are they in conveying data from one point to the next?
Punched tape
The first data transfer method is the punched tape. It consists of a long strip of paper with holes punched in it to store data. The holes represent a set of data that tells the machine how to move and what to do. This method has proven to be very versatile and very useful. It has proven to withstand the test of time as numerous magnetic storage devices have deteriorated over time even to the extent of being unreadable while punched tape has been shown to be fine decades and perhaps even centuries later. Repair is also not a problem as specially designed splices can put two end together virtually unchanged. Furthermore, punched tape can be visually decoded should the need arise. This means that human accessibility is also not a problem.
Floppy Disk
While punched tape is quite a long roll of paper, a floppy disk is a small magnetic storage device that is more space efficient than punched tape. It can also be used to store simple programs. Floppy disks virtually revolutionized the way data could be stored and transferred from one point to another. It allowed users to store and transfer data faster than punched tape allowed. Furthermore, the data within a floppy could be easily edited at any point as long as you have the proper program to read it. However, this method has proven to be quite problematic in the long run as floppies have a tendency to degrade alarmingly fast. A floppy could be unreadable after only 3 years.
RS232
This method is actually a set of standards for serial binary signals that connects between computers, terminals, and modems. This is a fast and efficient way to transfer data. This cable connects a CNC machine to a computer that has floppy disk support thus eliminating the need for punched tape. This allows the operator to input data remotely and even while accomplishing other tasks. However, it need to be used in conjunction with an effective data storage device so as to have backups in case of emergencies.
Networks
Networks are a set of computers that are linked together to make data sharing easier. In an industrial scenario, networks allow a number of different users to individually create a program for the machine to run on. This method allows multiple users to access and transfer data remotely. This allows for a faster and more efficient check-and-balance system for the programmer and the data verifier. Furthermore, different parts of the program can be completed by different programmers and then compiled by one user. This makes program creation a fast and easy process.
Manual Data Input
(MDI) MDI allows users to input commands directly into the CNC machine's memory. This may seem to be an effective way of telling the machine what to do but it actually has a lot of drawbacks to it. Despite it being the fastest way of telling the machine what to do, it is also a very risky and tedious operation as it requires the use of the machine's terminal. Furthermore, the construction of a program is not as fast as opposed to the network method. It only allows one user to access the machine thus making it a long and drawn-out process. Another disadvantage that comes with MDI is that it limits the operator to only one task at a time. However, MDI allows the most control over the machine compared to other methods.
Article Source: http://www.articlesbase.com/programming-articles/data-transfer-methods-of-cnc-581743.html
About the Author:
Gargi Nath,a Professor in English in a reputed college in kolkata for the last 5 years having done masters and Phd.A keen creative author and have written many articles on numerous topics.Many of the articles are published regularly in newspapers and magazines.Please visit my blog http://cnc-applications.blogspot.com for more information on Computer Numerically Controlled Machines.