6 FUNCTIONAL SAFETY
6.4 Safety sub-function
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SLI function
Outline
This function monitors whether the travel distance of the servo motor is within the specified range. If the travel distance of the
servo motor exceeds the specified permissible travel distance, the STO function is activated.
Operation sequence
The SLI function is activated by turning off SLIC (SLI command). The function starts monitoring right after SLIC (SLI
command) is turned off. The function monitors whether the travel distance after the position monitoring starts is within the
range specified by the parameter. The function monitors whether the travel distance in the address decreasing direction is
equal to or greater than the SLI permissible travel distance (negative direction), and the travel distance in the address
increasing direction is equal to or smaller than the SLI permissible travel distance (positive direction).
Monitoring ends by turning on SLIC (SLI command).
Position monitoring
■
Position feedback monitoring
During position monitoring, the function monitors whether the travel distance of the position feedback is within the SLI
permissible travel distance. Upon detection that the travel distance after the position monitoring starts exceeds the SLI
permissible travel distance, the STO function is activated. However, there will be a delay equal to the time set in [Pr. PSA17
Safety sub-function - Position detection delay time] from when the SLI permissible travel distance is exceeded until the STO
function is activated.
0 pulse
Feedback pulse
SLIC (SLI command)
ON (disabled)
OFF (enabled)
SLIS (SLI output)
Position monitoring
SLI permissible travel
distance (negative direction)
SLI permissible travel
distance (positive direction)
ON (disabled)
OFF (enabled)
0 pulse
ON
Feedback pulse
SLIC (SLI command)
ON (disabled)
OFF (enabled)
SLIS (SLI output)
Position monitoring
STO state
Position detection delay time
Feedback
Command
SLI permissible travel
distance (negative direction)
SLI permissible travel
distance (positive direction)
ON (disabled)
OFF (enabled)
STOS (STO output)
OFF (shut-off)