Omron NX-AD series, User Manual

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Terminology
32 NX-series Analog I/O Units User’s Manual for Analog Input Units and Analog Output Units (W522)
Operational --- A state in EtherCAT communications where SDO communications and
I/O are possible.
PDO communications --- An acronym for process data communications.
Pre-Operational --- A state in EtherCAT communications where only SDO communications
are possible with the slaves, i.e., no I/O can be performed.
primary periodic task --- The task with the highest priority.
process data --- Collection of application objects designated to be downloaded cyclically
or acyclically for the purpose of measurement and control.
process data communications --- One type of EtherCAT communications in which process data objects
(PDOs) are used to exchange information cyclically and in realtime. This
is also called PDO communications.
process data object PDO A structure that describes the mappings of parameters that have one or
more process data entities.
receive PDO RxPDO A process data object received by an EtherCAT slave.
Safe-Operational --- A state in EtherCAT communications where only SDO communications
and reading input data from slaves are possible. Outputs from slaves are
not performed.
SDO communications --- One type of EtherCAT communications in which service data objects
(SDOs) are used to transmit information whenever required.
service data object SDO CoE asynchronous mailbox communications where all objects in the
object dictionary can be read and written.
Slave Information Interface SII Slave information that is stored in non-volatile memory in the slave.
Slave Terminal --- A building-block remote I/O terminal to which a Communications Cou-
pler Unit and NX Units are mounted
subindex --- Sub-address of an object within the object dictionary.
Sync0 --- A signal that gives the interrupt timing based on the distributed clock
(DC) in EtherCAT communications. The slaves execute controls accord-
ing to this interrupt timing.
Sync Manager SM Collection of control elements to coordinate access to concurrently used
objects.
task period --- The interval at which the primary periodic task or a periodic task is exe-
cuted.
transmit PDO TxPDO A process data object sent from an EtherCAT slave.
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Description