STOBER
Glossary
02/2019 | ID 442728.05
253
Safe Stop 1 (SS1)
In accordance with DIN EN 61800-5-2: Procedure for stopping a PDS(SR). With the SS1
safety function, the PDS(SR) performs one of the following functions: a) Triggering and
controlling the motor delay variable within defined limits and triggering the STO function if
the motor speed falls below a specified limit value (SS1-d), or b) triggering and monitoring
the motor delay variable within defined limits and triggering the STO function if the motor
speed falls below a specified limit value (SS1-r), or c) triggering the motor delay and
triggering the STO function after an application-specific delay (SS1-t). In this case, SS1(-t)
corresponds to the time-controlled stop in accordance with IEC 60204-1, stop category 1(-t).
Safe Torque Off (STO)
In accordance with DIN EN 61800-5-2: Procedure for stopping a PDS(SR). The STO safety
function prevents the motor from being supplied with any energy that could cause rotation
(or motion in a linear motor). The PDS(SR) does not supply the motor with any energy that
could generate torque (or force in a linear motor). STO is the most fundamental drive-
integrated safety function. It corresponds to an uncontrolled stop in accordance with IEC
60204-1, stop category 0.
Safety Integrity Level (SIL)
In accordance with DIN EN 61800-5-2: Probability of a safety function failure. SIL is divided
into levels 1 – 4 (lowest – highest level). SIL precisely assesses systems or subsystems
based on the reliability of their safety functions. The higher the SIL, the safer and more
reliable the function in question is.
Self-discharge
Passive running process that causes the capacitors to discharge even when no electrical
load is connected.
Serial number
Consecutive number stored for a product in STOBER's enterprise resource planning system
and used for individual identification of the product and for determining the associated
customer information.
Single-ended (HTL/TTL)
In the context of signal transmission, electrical signal transmission takes place using a
voltage that changes in relation to a constant reference potential.
