View Full Version : Plc's programmed offline using a pc
May 14th, 2002, 05:01 AM
this is my first time here and I don't really know how basic the questions can be. Please forgive me if this is too basic a question... how are a plc and pc connected together and can I get a diagram from anywhere showing this? Can anyone tell me the advantages of using this system over a hand held programming panel?
May 14th, 2002, 06:34 AM
You're just going to have to put some more effort into it, chum. Crack the book and write back with better questions, and you'll get all the help you need.
May 14th, 2002, 06:36 AM
Ant you really should read Chapter 1 of your class book, then follow by reading the other chapters. Let's assume you arent a student and do not have a class book, buy Phil's book as a reference, read the tutorial on this site, read thru all the posts. There are a number of plc makers that have in depth support sites with manuals etc available that will explain alot in detail.
These questions are very basic so expect some razzing and READ READ
May 14th, 2002, 06:43 AM
There is no limit to how basic the questions can be. However, your questions sound like they're taken directly from your homework assignment. You'll find that we tend to be willing to help those who show a willingness to help themselves by doing the necessary background tasks such as paying attention in class and reading the assigned text.
I'm going to answer your questions with additional questions. I hope you'll be an exception from the students who normally post here. By that, I mean I hope you'll continue to post.
If you were the developer of programming software for PLCs, how would make the connection between the PC running the software and the PLC? Keep in mind that when this type of software was developed, the predominant operating system was DOS. Assuming that every manufacturer of PLCs approaches the task of programming differently, where would you expect to find specific information relating to the connections between the programming software and the PLC?
Understanding that both the hand-held programmer and the PC-based software can both program the PLC and monitor the operation, What additional desirable features might be available on a PC that are not available on a hand-held programmer?
May 14th, 2002, 07:11 AM
I am looking for some answers from a project we've been set. I'm doing a HNC day release course and we don't get class books we make notes on what the teacher tells us. This particular assignment requires us to search sources on the internet to find the relevant background knowledge.As this is the only tutorial site i repeatedly get sent to via my searches i thought i'd put a few questions in. As my occupation has very little to do with plc's i have very little knowledge on the subject and find it difficult to get to grips with. Once again i'd like to thank you for your time and hopefully with a little more time i can give you the required information on your questions. CHEERS
May 14th, 2002, 07:47 AM
OK, you seem willing to do some investigation, and I'll help a little. Allen's questions will be thought provoking, but a couple more hints might be in order.
A programming panel has little or no memory, and will only display a couple of rungs at a time, and doesn't allow documentation. What are the implications of that?
As far as connecting a PC to a PLC, the basic requirements are the same as any other communications system. You have to have a carrier for the message (think telephone line) and the two ends have to be electrically compatible (you can't hook a cable TV to your ordinary phone line, can you?) and the message has to be understood by both ends (can it work if you speak Spanish to a listener that knows only Russian?).
The answer to these questions and to your other two posts are contained in Phil's book and his tutorial. You should go through the tutorial first, and come back if you need further explanation of individual items. It will help if you quote the part of the titorial that is confusing you!