Leroy-Somer digitax st User Manual page 101

PROFIdrive profile: A standardised method of controlling drives that is independent of
the manufacturer.
Poll rate: The rate at which cyclic data is sent and received on the network.
PPO Modes: Different operational modes within the PROFIdrive profile. PPO 4 mode is
not the same as Mode 2 - PPO 4 Word mode non-cyclic data.
PPO 4 Word non-cyclic mode: see Mode 2 non-cyclic in this section. This is not the
same as PPO4 mode.
Response ID: The response code of the message received when using PPO4 word
non-cyclic communication.
Scan rate: See Poll rate in this section.
Segment: An electrically separate part of the network. Each segment requires correct
termination to ensure reliable operation. Due to electrical limitations the maximum
number of devices on a segment is limited to 32.
Shielding: A connection to provide additional noise immunity on a network cable.
Slave: A device on the PROFIBUS network such as a drive or sensor. A slave device
will only respond to messages from a master.
Status word: A value that denotes the status of the drive. Each bit within the word will
have a specific meaning.
SYNC: A method of preventing output state changes from being actioned by the slave,
until a SYNC signal is sent, this is used in conjunction with UNSYNC.
Task ID: The code used to describe the purpose of a message using PPO 4 word non-
cyclic communication.
Telegram: A message used within Mode 1 non-cyclic data communication. This term is
sometimes used to represent a generic message on the network.
Termination: This is used at both ends of a network segment to prevent reflections and
reduce noise. On PROFIBUS, termination is provided by a powered network of
resistors.
UNSYNC: Used to restore outputs in a slave to normal operation following a SYNC
command.
UNFREEZE: Used to restore inputs in a slave to normal operation following a FREEZE
command.
Watchdog: A method used to determine if a communication system is healthy. A typical
watchdog scheme uses a handshaking system to check both the master and slave are
participating in communications.
Word: A collection of 16 binary digits.
SM-PROFIBUS DP-V1 User Guide
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