Omron NX-SIH400, User Manual

Page: 162 / 626

Input Filters
The input filter helps prevent malfunctions that are sometimes caused by chattering or noise from the
external device that is connected to a safety input terminal.
You can filter out chattering and noise from the external device for the widths that are set with the ON
delay time and OFF delay time.
ON delays and OFF delays can be set to one of the 10 options given below, from 0 to 1,536 ms, for
each safety input terminal.
1: 0 [ms], 2: 6 [ms], 3: 12 [ms], 4: 24 [ms], 5: 48 [ms], 6: 96 [ms], 7: 192 [ms],
8: 384 [ms], 9: 768 [ms], 10: 1536 [ms],
The effect of chattering from external devices can be reduced more by increasing the delay time, but
this will slow the response to input signals.
The input filter can be used with dual channel evaluation.
Precautions for Correct Use
If an OFF delay is used, the OFF delay time affects the safety reaction time. Add the OFF delay
time to the safety reaction time. (Refer to
Section 8 Calculating Safety Reaction Times on
page 8 - 1.)
l
Operation with an ON Delay
You can filter out ON pulses for the width that is set with the ON delay time.
Internal timer
Safety input data
I/O indicator (yellow)
I/O indicator (red)
Safety input terminals
ON OFF ON
ON OFF
OFF
ON OFF
OFF ON Error
ON
*1
ON delay ON delay
Counter
cleared.
Counter
cleared.
Counter
cleared.
*1. This is the time that the error status (control data, status data, and indicator status) is held (1 s min.).
l
Operation with an OFF Delay
You can filter out OFF pulses for the width that is set with the OFF delay time.
4 Safety Control Unit Operation
4 - 30
NX-series Safety Control Unit User's Manual (Z930)