6 Incremental Encoder Input Units
6 - 28
NX-series Position Interface Units User’s Manual (W524)
With this I/O refreshing method, shortening the task period is given priority over synchronizing the I/O
timing with other NX Units. With this I/O refreshing method, the timing of I/O is not consistent with the
timing of I/O for NX Units that use simultaneous I/O refreshing.
*1. For an NX-series CPU Unit, the task period of the primary periodic task or priority-5 periodic task is applica-
ble. For an NJ-series CPU Unit, only the task period of the primary periodic task is applicable.
Note Refer to Operation for Task Period Prioritized Refreshing on page 5-10 for details.
Precautions for Correct Use
• If you use task period prioritized refreshing, set the task period to a value within the specified
refresh cycle range of the Position Interface Unit.
• If you use task period prioritized refreshing for the NX-EC022, the refresh cycle is 250 μs to
10 ms. If you operate the NX-EC022 at 125 μs, a WDT error will occur in the Incremental
Encoder Input Unit and the TS indicator will light red. An NX Unit Minor Fault error event will
occur in the Communications Coupler Unit at the same time.
6-6-4 Task Period Prioritized Refreshing
I/O refreshing
Data
processing
I/O refreshing
Data
processing
Controller
Incremental Encoder
Input Units
Controller cycle
time
*1
Position data Position data
Cycle to obtain position data
and to execute commands
Cycle to obtain position data
and to execute commands
Synchronization cycle