Input Refreshing With Input Changed Time - Omron NX-ID User Manual

5 I/O Refreshing
5-2-8

Input Refreshing with Input Changed Time

With this I/O refreshing method, the Input Units record the DC times when the inputs changed. The DC
times are not synchronized to the NX bus refresh cycles. Among Slave Terminals, only EtherCAT Slave
Terminals support this refreshing method.
The CPU Unit or EtherCAT Coupler Unit cyclically reads both the input values and the DC times when
the inputs changed on the NX bus refresh cycles.
In the descriptions below, the DC time when the input changed is called the input changed time.
You can use the Input Units that support input refreshing with input changed time with the Output Units
that support output refreshing with specified time stamp to control an output at a fixed interval after a
sensor input changes.
Description of Operation
CPU Unit operation
The following describes the operation of input refreshing with input changed time between the
NX-series NX1P2 CPU Unit and the NX Units.
• The NX Units that support input refreshing with input changed time record the DC times when an
input changes for each input bit. The DC times that the Units record are the DC times for which
the status changes of the input terminals passed the ON/OFF response time and reached the
internal circuits.
• The CPU Unit reads the input values and the input changed times from the NX Units at I/O
refreshing. The input values that the CPU Unit reads are not the input values at the point when the
input change times were recorded, but the input values at I/O refreshing.
• All Digital Input Units that operate with input refreshing with input changed times and are con-
nected to the CPU Unit read the input changed times at the same time at a fixed interval based on
synchronization timing. (Refer to (a) in the figure below.)
• The timing of reading input changed times is the same as the timing at which all Digital Input Units
and Analog Input Units that operate with synchronous input refreshing and are connected to the
CPU Unit read their inputs.
• The timing of reading input values is at I/O refreshing, which is different from the timing of reading
input changed times.
• The CPU Unit reads the input changed times and input values at immediate I/O refreshing after
the input changed times are read. (Refer to (b) in the figure below.)
• The interval of I/O refreshing varies with the processing conditions of the CPU Unit. (Refer to (c) in
the figure below.) The timing to read input changed times will be at a fixed interval. (Refer to (d)
and (e) in the figure below.)
• The timing of reading input changed times, the synchronization timing, and the maximum NX bus
I/O refresh cycle are automatically calculated by the Sysmac Studio according to the input refresh
cycles of the NX Units on the CPU Unit when a Unit Configuration in the CPU Unit is created and
set up.
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NX-series Digital I/O Unit User's Manual (W521)