Mitsubishi Electric MR-D30 Instruction Manual page 108

4. SAFETY OBSERVATION FUNCTION
(c) Position feedback observation during a stop
This observes that an absolute value of the position feedback variation from the start of the stop
observation (SOS) is within the set value of [Pr. PSA05 SOS allowance value of position deviation]
during stop observation. When the travel distance exceeding the set value of [Pr. PSA05 SOS
allowance value of position deviation] is detected, the STO function will start.
Feedback pulses
SS2C (SS2 command)
ALM (Malfunction)
Base circuit
(Energy supply to
the servo motor)
STOS (STO output)
SOSS (SOS output)
(5) Parameter setting
To set the parameters, refer section 4.3.3. When using the SS2/SOS function in the safety observation
function control by input device, refer to 4.4.1 to set parameters. When using the SS2/SOS function in
the safety observation function control by network, refer to 4.4.3 to set parameters. Additionally, when
using SS2S (SS2 output) and SOSS (SOS output) with output devices, refer to 4.4.2 to set parameters.
To use the SS2/SOS function, a servo motor with functional safety is required. Refer to section 4.4.4 for
servo motors with functional safety. When using the SS2/SOS function, set the parameters as follows.
(a) SS1/SS2 monitoring deceleration time
Set enough time for the servo motor to stop referring to operation sequence.
(b) SS2/SOS standstill speed
Set servo motor speed which the servo motor is assumed as stopped referring to operation
sequence.
(c) SOS allowance value of position deviation, SOS allowance value of position deviation unit selection
Set an allowance value of position deviation during stop observation referring to the operation
sequence.
Command
0 pulse
ON (disabled)
OFF (enabled)
ON (no alarm)
OFF (alarm)
ON
OFF
ON
OFF (shut-off)
ON (observation
in progress)
OFF
Parameter
PSA03 SS1/SS2 monitoring deceleration time
PSA04 SS2/SOS standstill speed
PSA05 SOS allowance value of position deviation
PSA06 SOS allowance value of position deviation unit selection
PSA15 SLS/SS2/SOS speed detection delay time
PSA17 SOS position detection delay time
4 - 37
Deceleration Stop observation (SOS)
Feedback
STO status
SOS allowance
value of position
deviation
Name