Profibus Modbus EGX IJBs...need help understand

Hiya, In the past I have worked with AB PLCs, Citect, DH+ but I have recently changed jobs and struggling with the changes. Sometimes dont know where should I start. At this new job we are using all Schneider products....I am based in Melbourne if someone is willing to help I am happy to pay and I'll really appreciate it...I need some help understanding the following:
1/ Schneider architecture...or products...What are the different types of PLCs.. there is so much happening,,,ethernet, modbus, fibre optic...im lost
2/ Remote I/O
3/ IJBs
4/ EGX
5/ Modbus
6/ Profibus DP
7/ Profibus PA

Please guide to me where I can learn from...find reading material....and other bits n things...

Cheers :0

There is a website for Modbus:
http://www.modbus.org/

Profibus:
http://www.profibus.com/downloads/

Patrick Lansdorf
FAE
HMS Industrial Networks

I'm not a Schneider guy, but here's my take on Modbus.

It's my impression that Schneider now owns the remnants of Modicon, who invented Modbus, and that they're the main source of Modbus Plus.

Modbus Plus differs from generic Modbus in that Modbus Plus is not limited to a single master, rather there is a token passing scheme so the mulitiple masters can rotate as to who's the current master. This is used for fast update rack to rack communications. Modbus Plus is a licensed technology.

Generic Modbus is an open protocol (not licensed). The standards are downloadable (see link above). Hence, there are tens of thousands of implementations of various degrees.

Generic Modbus RTU (over serial RS-485 typically) has one master only.

Generic Modbus/TCP is essentially Modbus RTU over ethernet, but since ethernet TCP/IP does hold and forward in its switches, Modbus/TCP can theoretically handle multiple masters.