Rockwell Automation 20-COMM-ER 20-COMM-ER Dual-Port EtherNet/IP Communication Adapter User Manual - Manual (Page 227)

Rockwell Automation Publication 20COMM-UM015B-EN-P - July 2013 227
Glossary
M
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 EtherNet/IP adapters) are
slave devices.
On a network with multiple scanners (called a multimaster hierarchy), each slave
device must have a scanner specified as a master.
N
NVS (Nonvolatile Storage)
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’.
P
PCCC (Programmable Controller Communications Command)
PCCC is the protocol used by some controllers to communicate with devices on
a network. Some software products (for example, DriveExplorer and
DriveExecutive software) also use PCCC to communicate.
Peer-to-Peer Hierarchy
An adapter that is configured for a peer-to-peer hierarchy can exchange data with
a device on the network that is not a scanner. This type of hierarchy can be set up
so that a scanner configures or transmits data to one PowerFlex 7-Class drive
which then sends the same configuration or data to other PowerFlex 7-Class
drives on the network. To use a peer-to-peer hierarchy, you configure one adapter
to transmit data (2 or 4 words) and one or more adapters to receive the data.
Ping
A message that is sent by a DPI product to its peripheral devices. They use the
ping to gather data about the product, including whether it can receive messages
and whether they can log in for control. On EtherNet/IP, a ping can be used to
determine if a node exists.
PowerFlex 7-Class (Architecture Class) Drives
The Allen-Bradley PowerFlex 7-Class family of drives supports DPI and, at the
time of publication, includes the PowerFlex 70, PowerFlex 700, PowerFlex 700H,
PowerFlex 700S, PowerFlex 700L, and PowerFlex 7000 drives.
R
Reference/Feedback
The Reference is used to send a setpoint (for example, speed, frequency, and
torque) to the drive. It consists of one word of output to the adapter from the