Confused by Active and Passive-Master/Slave!

HI,
Can tell me the defination of these terms -Master/SLave and Active/Passive in automation field?

I found: in computer networking, master/slave is a model for a communication protocol in which one device or process (known as the master) controls one or more other devices or processes (known as slaves). Once the master/slave relationship is established, the direction of control is always from the master to the slave(s). The County of Los Angeles, saying the term master/slave may be offensive to some of its residents, has asked equipment manufacturers not to use the term. Some manufacturers prefer the term primary/secondary.
Other communication protocol models include the client/server model, in which a server program responds to requests from a client program, and the peer-to-peer model, in which either of the two devices involved can initiate a communication session.

cheer

Master Slave network will have one and only one master, who can initiate a messgae to read/write to any slave device on the network. All slave device will just respond to a request from the Master. A slave device cannot directly communicate to another slave device. A slightly advanced version of this is called MSTP ( Master Slave Token Passing ). In an MSTP network, a token is passed among the devices in the network and when one device gets the token, it can act as a master and request read/write to any other device. The token is passed from once device to another based on the ascending node number and each device get chance to be a master for some time.
Active network generally needs a power supply on the wire where passive network dont require power ( eg. thermocouple, RTD etc. )

Hello apel;
In your post I find no mention of passive/active definitions in communication networks. Could you please give an example where the opposition master/slave and passive/active is determined? maybe we could understand the question better.
Regards,
Daniel Chartier

Concerning the controversy over terminology - not to be a knee-jerk politically correct person - but I believe that 'master/slave' does not quickly and accurately convey the communication relationship. I like 'initiator/responder' myself.

Dear Daniel Chartier,
I am doing one simple communication job right now and confused by two manuals.One device is Schenk Weigher MULTICONT which is serial RK512/3964R protocol device and is 'Slave Device'.This device is to be connected with one Serial to Profibus-Dp gate(this gate is called Passive device)...now the probelem is that who will initiate communication between serial and Probibus Dp....gateway is connected with ProfibusDp master.

confused! again