Schneider Electric Processor Adapter manual How I/OBus Works

Using the I/OBus Port

How I/OBus Works

Introduction	This section describes how signals are passed and how data is transferred in an
	I/OBus network.
How Signals Are
	I/OBus operates as a logical ring, with signals being passed by the master over a
Passed	remote bus cable to each slave device in series. The slaves return signals to the
	master over the same cable.
How Data is
	The I/OBus functions as a logical shift register. The application’s entire data stream,
Transferred	originating at the master, is transferred serially from slave to slave down the remote
	bus. Each slave regenerates the entire stream before passing it on. As a slave
	handles the stream data, it extracts the portion that is assigned to it and adds any
	output data to the stream.
Transmission
	Data is transmitted at 500 kbits/s.
Speed

Amount of data The number of 16 bit words in the data stream is dependent on the processor model:

Model	Max Input Words	Max Output Words
171 CCS 760 00	128	128
171 CCC 760 10	256	256
171 CCC 960 20	256	256
171 CCC 960 30	256	256

Note: Processors that support IEC are limited to a maximum number of 1408 used I/O points, regardless of the number of modules.

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