Rockwell Automation 20-COMM-H RS485 HVAC Adapter FRN 2.xxx - Manual (Page 91)

20-COMM-H RS-485 HVAC Adapter User Manual
Publication 20COMM-UM009D-EN-P
Glossary
A Adapter
Devices such as drives, controllers, and computers usually require an
adapter to provide a communication interface between them and a network.
An adapter reads data on the network and transmits it to the connected
device. It also reads data in the device and transmits it to the network.
The 20-COMM-H RS-485 HVAC adapter connects a PowerFlex 7-Class
drive to the network. Adapters are sometimes also called “cards,”
“embedded communication options,” “gateways,” “modules,” and
“peripherals.”
B Bus Off
A condition that occurs when an abnormal rate of errors is detected in a
device. The bus off device cannot receive or transmit messages on the
network. This condition is often caused by corruption of the network data
signals due to noise or data rate mismatch.
C ControlFLASH
An Allen-Bradley software tool that lets users electronically update
firmware on printed circuit boards. The tool takes advantage of the growing
use of flash memory (electronic erasable chips) across industrial control
products.
Controller
A controller, also called programmable logic controller, is a solid-state
control system that has a user-programmable memory for storage of
instructions to implement specific functions such as I/O control, logic,
timing, counting, report generation, communication, arithmetic, and data
file manipulation. A controller consists of a central processor, input/output
interface, and memory. See also Scanner.
D Data Rate
The speed at which data is transferred on the network. Each device on a
network must be set to the same data rate.
Datalinks
A Datalink is a type of pointer used by some PowerFlex drives to transfer
data to and from the controller. Datalinks allow specified parameter value(s)
to be accessed or changed without using explicit messages. When enabled,
each Datalink consumes either four bytes or eight bytes in both the input
and output image table of the controller. The drive determines the size of
Datalinks.
DPI (Drive Peripheral Interface)
A second generation peripheral communication interface used by various
Allen-Bradley drives and power products, such as PowerFlex 7-Class
drives.