346
6 FUNCTIONAL SAFETY
6.4 Safety sub-function
■
Noise elimination filter
• Outline
The noise elimination filter is a function to set a filtering time to reduce the noise of input signals. Set the filtering time of the
noise elimination filter with [Pr. PSD12 Input device - Noise elimination filter time DI1].
The longer the noise elimination filter time, the better the resistance to chattering and noise, but the slower the response to
the input signals. The shorter the noise elimination filter time, the faster the response to the input signals, but the less
resistance to chattering and noise.
When the test pulses are superimposed on the input signals, the noise elimination filter time needs to be set considering the
off-time of the test pulses. The following table shows the specific settings of the noise elimination filter time.
• Setting functional safety parameters
For input devices to which the function is assigned with [Pr. PSD02 Input device selection DI1], set the noise elimination filter
time in [Pr. PSD12 Input device - Noise elimination filter time DI1].
Because the response time of the input device changes according to the noise elimination filter time, refer also to the
following.
Page 346 Response time of input device
■
Response time of input device
The response time of the input device changes according to the noise elimination filter time set in [Pr. PSD12 Input device -
Noise elimination filter time DI1].
The following shows a sequence when STOC (STO command) is assigned to the input signal of the CN8-4/CN8-5 pin. A
delay equal to the input device noise elimination filter time occurs in the response time from when signals are input to input
devices until the corresponding functions switch between enabled/disabled.
Configuration
Noise elimination filter time
Using a switch
Set 1.00 ms or more.
Using a device
Test pulses are in superposition in the
output signal of the device.
Set a time that is at least 1.00 ms longer than the off time for test pulses
outputted by the machine.
Test pulses are not in superposition in
the output signal of the device.
Set 1.00 ms or more.
Parameter
Name
PSD12
Input device - Noise elimination filter time DI1
ON
OFF
ON
OFF
ON
OFF
ON
STOC (STO command)
ON (disabled)
OFF (enabled)
Base circuit
(energy supply to
servo motor)
STOS (STO output)
OFF (shut-off)
Input device noise elimination filter time
CN8-4 pin
CN8-5 pin