frustrated british student

[Guest Barnaby Augustus Smith]

Ok, i was wondering if anyone would be able to help me with this; as part of a PLC's assignment for my apprenticeship, i need to briefly explain what is meant by the terms "network standards" eg RS232 and "network protocols" eg MAP, in relation to PLC's in general and the mitsubishi A1S in particular. It only needs to be brief, so that i can show a "general understanding" of the topic (this i blatantly don't have) so, any help would be greatly appreiciated. my email address is ninjabarnaby@hotmail.com Thanks very much, Barnaby

[navillusi 2]

A good introduction and theory of PLC networks, e.g. RS232 can be found in the downloadable PLC book by Hugh Jack which is on this sites frontpage. You can select the chapters to download as you wish, i.e. serial comms, this book is very informative and certainly worth a read. Here you will find details of all the standards. As far as Mitsubishi A1s processors are concerned, the CPU connection is a RS422 interface only, how the PLC communicates then to other devices depends upon what type of comms card you buy, there are many, Melsecnet, Ethernet, Devicenet, ASI, Profibus, CC-Link, RS232, RS422, RS485 (to name but a few). If you know what network type you are dealing with on the A1s, Mitsubishi's manuals can also be found on-line which would give you more reference material. Regards