Octagon 6000 Series, User Manual

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Serial ports 6000 Series user’s manual
Up to 32 nodes with valid ID range from 0 to FF are supported. ID 0 is
reserved for the host. ID FF is reserved for a new node that connects to
the network and has not yet been assigned an ID.
Both input and output ring buffer size is 2 KB.
Host/remotes
An application may implement a node as either the “host” node or as a
“remote” node in an RS-422/485 network. There can be up to 32 nodes
without any bus repeaters in the network. A “host” is referred to as the
node that initiates a communication; while a “remote” is referred to as a
node that is addressed by the host.
The host is responsible for initiating communication, maintaining
network registration, and providing housekeeping tasks with other
nodes. There can only be one network host.
Remotes cannot initiate a communication. They can only respond to
messages that are addressed to them from the host.
While there can be many remotes, all remotes initially respond to FFh
as the ID before the ID is assigned or recognized by the host. To avoid
conflict, only one new node at a time shall be added to the network.
Other unregistered nodes must not be powered up while the new node is
being registered. This allows assigning each node a unique node ID.
Once a node has been added to the network and its ID stored in serial
EEPROM, any node can thereafter attach to the network in any
powerup sequence. Periodically, the host shall try to communicate to all
the existing nodes in the network, plus the potential new node with the
ID FFh.
Network interface module (NIM)
The Octagon network interface module (NIM) is designed for easy
installation onto COM2 of the PC Microcontrollers. The NIM supports
four-wire RS-422 and two-wire RS-485 configurations. Power is sup-
plied to the NIM via the COM2 connector on the PC Microcontroller.
For more information about the network interface module, see the NIM
product sheet.
Note The network interface module is not compatible with the 6010 model.