peer-to-peer communication
A communication between networked devices in which any device can initiate data transfer. The method used by devices conforming to the OSI Model. Also the method used on Modbus Plus.
Physical Layer
In the OSI model, the layer that provides the physical connection and signalling means between nodes of a network. Defined by the I 802.4 standard.
port
The external connector on a device at which the network cable is attached.
protocol
A set of rules used mutually by two or more devices to communicate.
Repeater
A Modicon device that interconnects two sections of a Modbus Plus network.
routing path
In Modbus Plus, the sequence of device node addresses through which a message will be routed to its final destination.
routing path field
In a Modbus Plus message frame, a group of five bytes that specify the addresses of the devices in the message routing path.
RS232
An IA standard that defines signal requirements and cable connections for serial data communications, characterized by single wires for transmitted data and received data.
RS485
An IA standard that defines signal requirements and cable connections for serial data communications, characterized by a balanced pair of wires for both transmitted and received data.
section
A contiguous grouping of cable segments, together with their node devices, connected directly to form a signal path that does not pass through any Repeater. The minimum length of a section can be 10//ft (3//m), the same as one segment. The maximum length can be 1500 ft (450 m). One section supports up to 32 nodes.
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