6 FUNCTIONAL SAFETY
6.4 Safety sub-function
357
6
SS1 function
Outline
This function starts deceleration with input signals from external devices. After the specified time to confirm the motor stop,
the STO function is executed (SS1). This is equivalent to the stop category 1 of IEC/EN 60204-1.
Since the SS1 function is also used for emergency stop when an internal diagnostic error is detected, refer to the following to
set the functional safety parameters.
Page 363 Setting functional safety parameters
There are two types of SS1 function: time monitoring and deceleration monitoring. Deceleration monitoring uses encoder
information to monitor whether deceleration is performed correctly. Deceleration monitoring can be switched with [Pr. PSA02
Functional safety setting].
Sequence outline
■
SS1C (SS1 command)
The operation sequence of the time monitoring function of the SS1 function is shown below.
The SS1 function is activated by turning off SS1C (SS1 command). First, the servo motor decelerates by either the dynamic
brake, electronic dynamic brake, or forced stop. At the same time, the time from when the SS1 function is activated is
measured, and the STO function is activated when the time set in [Pr. PSA03 SS1/SS2 deceleration monitor time] has
elapsed. The servo motor returns to normal operation by turning SS1C (SS1 command) back on.
ON
0 r/min
(mm/s)
ON
Servo motor speed
SS1C (SS1 command)
ON (disabled)
OFF (enabled)
WNG (warning)
ON (enabled)
OFF (disabled)
STOS (STO output)
OFF (shut-off)
SS1S (SS1 output)
OFF (shut-off)
SS1/SS2 deceleration
monitor time
SS1 in progress
STO state