Yaskawa SmartTrac PCIM Card - Manual (Page 9)

SMART TRAC Genius PCIM Card
Technical Manual 3554-0080 Genius Basics
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Genius Basics
Introduction
Developed by General Electric, the Genius network provides an industrial
networking scheme with software-configurable fault reporting, input filter time,
overload detection, and I/O mix. Programmable inputs and outputs, part of
Genius I/O Blocks, allow any circuit to be set up for either input or output. This
means that one 8-circuit block is field-configurable to any of 256 distinct
combinations of inputs and outputs.
A Genius network passes a token in what are called bus scans. The pass starts at
the controller, which passes the token to the first node. It is next passed on
through consecutively numbered nodes. When it gets the token, a node can send
messages. When done sending, it notifies the network that it is done and passes
the token to the node with the next highest address. Finally, the token is passed
to either node 15 or 31 (the baud rate and cable type determine the maximum
number of nodes). The process repeats.
NOTE: Node 31 is generally reserved for a CPU. Nodes 29 and 30 are generally
reserved for fault tolerant devices.
In each bus scan, inputs are broadcast to all CPUs on the bus. The CPUs send
outputs to specific nodes, as required. Typically, node 31 is the CPU
Information may also be sent using Datagrams. Each datagram includes source-
to-destination routing information. During each bus scan, one datagram may be
automatically sent from one node to another, specific node. It may also be sent
from the PLC or computer to I/O blocks. Each datagram may contain up to 128
bytes of data.
Nodes in a Genius network may automatically broadcast up to 128 bytes of
global data with each bus scan. All CPUs on the bus receive all broadcasts of
global data. The receiving nodes do not acknowledge receipt of global data.
Upon receipt of data, the receiving node performs a cyclic redundancy check
(CRC) to ensure data integrity.
Two or more buses may be used, for example, to split activity to I/O information
on one bus and communications information on another.