Term
Abbre-
viation
Description
object dictionary
OD
Data structure that contains description of data type objects, communi-
cation objects and application objects.
Operational
---
A state in which I/O refresh communications and NX message commu-
nications are possible between the communications master and the
Communications Coupler Unit or NX Units.
service data object
SDO
CoE asynchronous mailbox communications where all objects in the
object dictionary can be read and written.
differential input
---
A method of reading the difference between a positive analog output
signal and a negative analog output signal, which are input to the Unit
from the output device.
subindex
---
Sub-address of an object within the object dictionary.
sampling period
---
The period during which the sampling of analog input data is performed
in an NX-series High-speed Analog Input Unit.
receive PDO
RxPDO
A process data object received by an EtherCAT slave.
Sync Manager
SM
Collection of control elements to coordinate access to concurrently
used objects.
single-ended input
---
A method of reading the difference between the ground and a positive
analog output signal, which is input to the Unit from the output device.
Slave Terminal
---
A building-block remote I/O terminal, which consists of a Communica-
tion Coupler Unit connected with NX Units.
Safe-Operational
---
A state in which input refresh communications and NX message com-
munications are possible between the communications master and the
Communications Coupler Unit or NX Units, but output refresh commu-
nications are not possible.
transmit PDO
TxPDO
A process data object sent from an EtherCAT slave.
task period
---
The interval at which the primary periodic task or a periodic task is exe-
cuted.
Communications Coupler Units
---
The generic name of an interface unit for remote I/O communications
on a network between NX Units and a host network master.
distributed clock
DC
Clock distribution mechanism used to synchronize EtherCAT slaves
and the EtherCAT master.
Digital Filter Processing Period
---
The period during which the processing of the digital low-pass filter and
moving average filters is executed.
device profile
---
A collection of device dependent information and functionality providing
consistency between similar devices of the same device type.
device variable
---
A variable that is used to access a specific device through an I/O port
by an NJ/NX-series CPU Unit or NY-series Industrial PC.
Process data on an EtherCAT slave is allocated to this variable. For
NX-series CPU Units to which NX Units can be connected, I/O data for
the NX Units on a CPU Unit is allocated. A user application on a CPU
Unit or Industrial PC accesses a device that can be connected, by di-
rectly reading and writing this device variable.
Trigger Input Time Stamp
---
The DC time at which the trigger input changes from OFF to ON during
the NX bus I/O refresh cycle of an NX-series High-speed Analog Input
Unit. If the trigger input changes from OFF to ON more than once dur-
ing the cycle, the DC time at the first change is recorded.
network configuration information
---
The EtherCAT network configuration information held by the EtherCAT
master.
primary periodic task
---
The task with the highest priority.
Terminology
36
NX-series Analog I/O Units User’s Manual for High-speed Analog Input Units (W592)
