Momentum Sales & Marketing 170 PNT Series manual How Messages are Transacted

Communication Adapter Message Handling

How Messages are Transacted

Overview	This section explains how a Communication Adapter relays information between its
	I/O base and a programmable controller.
The Right to
	A token frame is passed from node to node in a rotating address sequence. The
Transmit	node currently holding the token has the sole right to transmit. All other nodes
	monitor the network and extract messages addressed to them.
Messages from
	When a Communication Adapter at an input base module acquires the token, it
Communication	transmits its message to the programmable controller node. The message data
Adapters	describes the current states of the signals at the base’s field input terminals.
	The controller reads the message and steers its contents into the data registers
	defined for that adapter’s address in the controller’s Peer Cop table.
Messages to
	When the programmable controller acquires the token, it transmits its messages to
Communication	the Communication Adapters. Messages are sent to the node addresses defined in
Adapters	the controller’s Peer Cop table, with the message contents taken from the data
	registers defined in the table.
	Each Communication Adapter at an Output base module uses its received message
	to control the field devices connected to the base’s output terminals.

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