Rockwell Automation 22-COMM-D DeviceNet Adapter - Manual (Page 129)

Glossary-5
Flash Update
The process of updating firmware in the adapter. The adapter can be
flash updated using the X-Modem protocol and a 1203-SSS Smart
Self-powered Serial converter (firmware 3.xx).
H
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.
HIM (Human Interface Module)
A device that can be used to configure and control a PowerFlex 4-Class
drive. PowerFlex 4-Class HIMs (22-HIM-*) can be used to configure
connected peripherals.
Hold Last
When communications are disrupted (for example, a cable is
disconnected), the adapter and PowerFlex 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 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.
L
Logic Command/Logic Status
The Logic Command is used to control the PowerFlex 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 PowerFlex 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.