2 - Fagor Automation

Functional safety
9.
FUNCTIONAL SAFETY
Examples
326
DDS
HARDWARE
Ref.1307
316
9.3 Examples
Note. These examples use an external safety relay.
Example 1. STO (Safe Torque Off) safety function with PL d or SIL 2
This STO safety function corresponds to an uncontrolled stop in accordance
with stop category 0 of IEC 60204-1.
KM1 auxiliary contact of - KM1 with EN 60947-5-1 approval
F. H9/2
STO safety function (with PL d or SIL 2) monitoring the status of both
channels with an external safety relay.
Example 2. SS1 (Safe Stop 1) safety function with PL d or SIL 2
This SS1 safety function corresponds to a controlled stop in accordance
with stop category 1 of IEC 60204-1.
When requiring an SS1 safety function, it is necessary to use a safety relay
with delayed contacts and non-delayed contacts so as to do a controlled
stop before removing motor torque. See an example with this type
of operation.
KM1 auxiliary contact of - KM1 with EN 60947-5-1 approval
State definition: Drive Enable = 0 Torque Off Positive logic
F. H9/3
SS1 safety function (with PL d or SIL 2).