Rockwell Automation 20-COMM-K CANopen Adapter User Manual
Page 115
Glossary
G-7
20-COMM-K CANopen Adapter User Manual
Publication 20COMM-UM012B-EN-P
R
Reference/Feedback
The Reference is used to send a setpoint (for example, speed, frequency,
torque) to the drive. It consists of one word of output to the adapter from the
network. The size of the word (either a 16-bit word or 32-bit word) is
determined by the drive.
Feedback is used to monitor the speed of the drive. It consists of one word
of input from the adapter to the network. The size of the word (either a
16-bit word or 32-bit word) is determined by the drive.
Remote Transmission Request (RTR)
A PDO can be remotely requested. The PDO consumer transmits a CAN
remote frame and the corresponding PDO producer responds to this remote
frame by sending the requested PDO. This is also called “Polled I/O Data
Exchange.”
S
Scanner
A scanner is a separate module (of a multi-module controller) or a built-in
component (of a single-module controller) that provides communication
with adapters connected to a network. See also Controller.
SDO (Service Data Objects)
Service Data Objects (SDO) are used to transfer data that does not require
continuous updates. A SDO reads from entries or writes to entries of the
Object Dictionary. The SDO transport protocol allows transmitting objects
of any size. The receiver confirms each object, so that a peer-to-peer
communication (client/server) takes place.
Status Indicators
Status indicators are LEDs that are used to report the status of the adapter,
network, and drive. They are on the adapter and can be viewed on the front
cover of the drive when the drive is powered.
Synchronization Object (Sync)
The Sync object is used for synchronizing devices and is broadcast
periodically by the Sync Producer. The time period between Sync messages
is defined by the Communication Cycle Period.
T
Transmission Mode
See Transmission Type.
Transmission Type
The transmission type parameter of a PDO specifies the transmission mode
(synchronous or asynchronous) and the triggering mode. In CANopen, there
are three types of PDO triggering: COS (Change of State), Cyclic
Transmission, and Remote Transmission Request (RTR).
Triggering Mode
See Transmission Type.