YASKAWA E-V Series User Manual page 87

(4) Error Detection for Safety Request Input Signals
The Safety Module monitors the state of redundant Safety Request Input Signals allocated to each safety func-
tion to detect errors.
The process of error detection is as follows:
1. The time period until the ON/OFF state of the redundant Safety Request Input Signals matches is mea-
sured.
2. If the measured time period exceeds the specified time period, an error is detected in the Safety Request
Input Signal.
3. The power supply to the motor is shut OFF by executing the HWBB function of the SERVOPACK.
 Time Measurement Timing
The timing of measuring the time period until the ON/OFF state of the redundant Safety Request Input Signals
match is described below.
• Measurement starts when the edge of either the SRI-A1 signal or SRI-A2 signal is detected.
• The condition for ending measurement depends on the condition when measurement was started.
The conditions for starting and ending the measurement of time period are as follows:
Condition for
Starting Measurement
When either the SRI-A1 signal
or SRI-A2 signal changes from
ON to OFF
When either the SRI-A1 signal
or SRI-A2 signal changes from
OFF to ON
Measurement ends when both the Safety Request Input Signals turn OFF.
Measurement ends when both the Safety Request Input Signals turn ON.
Operation Timing
SRI-A1 signal
ON OFF
SRI-A2 signal
ON
Time measurement is not stopped here.
SRI-A1 signal
OFF ON
SRI-A2 signal
OFF
Time measurement is not stopped here.
tm: Measured time
Condition for Ending Measurement
ON OFF
tm
OFF
OFF ON
tm
ON
6.2 Common Items
6-5