1) risk assessment, 2) hard wire base block (hwbb) state, M-iii – Yaskawa Sigma-5 User Manual: Design and Maintenance - Linear Motors MECHATROLINK-III Communications Reference User Manual
Page 139

4.9 Safety Function
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4
Op
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(1) Risk Assessment
When using the HWBB function, be sure to perform a risk assessment of the servo system in advance. Make
sure that the safety level of the standards is met. For details about the standards, refer to Harmonized Stan-
dards at the front of this manual.
Note: To meet the performance level d (PLd) in EN ISO 13849-1, the EDM signal must be monitored by a host controller.
If the EDM signal is not monitored by a host controller, the system only qualifies for the performance level c (PLc).
The following risks can be estimated even if the HWBB function is used. These risks must be included in the
risk assessment.
• The servomotor will move in an application where external force is applied to the servomotor (for example,
gravity on the vertical axis). Take measures to secure the servomotor, such as installing a mechanical brake.
• The servomotor may move within the electric angle of 180 degrees in case of the power module failure, etc.
Make sure that safety is ensured even in that situation. The movement distance depends on the motor type.
The maximum movement distance is given below.
Linear motor: 50 mm max.
• The HWBB function does not shut off the power to the SERVOPACK or electrically isolate it. Take mea-
sures to shut off the power to the SERVOPACK when performing maintenance on it.
(2) Hard Wire Base Block (HWBB) State
The SERVOPACK will be in the following state if the HWBB function operates. If the /HWBB1 or /HWBB2
signal is OFF, the HWBB function will operate and the SERVOPACK will enter a hard wire baseblock
(HWBB) state.
/HWBB1
/HWBB2
M-
III command
Servo command
status SV_ON
Servo command
status SV_ON
Motion
command, etc.
SV_OFF
command
1
0
0
1
SMON
command, etc.
Servo command input
signal monitoring ESTP
SERVOPACK
state
ON
(Normal operation)
OFF
(Motor current shut-off
request.)
HWBB state
BB state
Operation
1
0
0
1
Motion
command, etc.
SMON
command, etc.
/HWBB1
/HWBB2
M-
III command
Servo command input
signal monitoring ESTP
SERVOPACK
state
ON
(Normal operation)
OFF
(Motor current shut-off request.)
HWBB state
Operation
The HWBB function operates after the servomotor power is turned OFF.
The HWBB function operates while the servomotor power is ON.
M-III