Rockwell Automation RECOMM-DNET DeviceNet Adapter for use with DPI AC Drives - Manual (Page 160)

Glossary-4 DeviceNet Adapter for use with DPI AC Drives
heartbeat rate - The heartbeat rate is used in change of state
(COS) data exchange. It is associated with producing data once
every EPR (Expected Packet Rate) duration. There may be four
heartbeats before a time-out happens.
hold last - When communications are disrupted (for example, a
cable is disconnected), the adapter and SP600 drive can respond
by holding last. Hold last results in the drive receiving the last data
received via the DeviceNet connection before the disruption. If the
drive was running and using the reference from the adapter, it will
continue to run at the same reference.
I/O data - I/O data, sometimes called “implicit messages” or “input/
output,” transmit time-critical data such as a Logic Command and
Reference. The terms “input” and “output” are defined from the
scanner’s point of view. Output is transmitted by the scanner and
consumed by the adapter. Input is transmitted by the adapter and
consumed by the scanner.
Logic Command/Logic Status - The Logic Command is used to
control the SP600 drive (e.g., start, stop, direction). It consists of
one 16-bit word of input to the adapter from the network. The
definitions of the bits in this word depend on the drive.
The Logic Status is used to monitor the SP600 drive (for example,
operating state, motor direction). It consists of one 16-bit word of
output from the adapter to the network. The definitions of the bits in
this word depend on the drive.
master-slave hierarchy - An adapter configured for a master-slave
hierarchy exchanges data with the master device. Usually, a
network has one scanner which is the master device, and all other
devices (for example, drives connected to DeviceNet adapters) are
slave devices.
On a network with multiple scanners (called a multimaster
hierarchy), each slave device must have a scanner specified as its
master.
node address - A DeviceNet network can have as many as 64
devices connected to it. Each device on the network must have a
unique node address between 0 and 63. Node address 63 is the
default used by uncommissioned devices. Node addresses are
sometimes called “MAC IDs.”
non-volatile storage (NVS) - NVS is the permanent memory of a
device. Devices such as the adapter and drive store parameters and
other information in NVS so that they are not lost when the device
loses power. NVS is sometimes called “EEPROM.”
object - The DeviceNet specification defines an object as “an
abstract representation of a particular component within a product.”