WAGO -I/O-SYSTEM 750 Manual page 142

142 Glossary
Overvoltage Category
The overvoltage category is in indicator for the overvoltages, for example, that
can occur at the place if installation due to lightening or switching operations.
P
Passivate, passivation
Passivation of safe digital inputs or power outputs is performed automatically by
the F I/O module after activation or detection of errors. Operator
acknowledgement is required after passivation, so that the F I/O module can
start.
PE (Protective Earth)
The PE is connected to the ground connector according to EN 60204-1 and is
used as fundamental protection against electric shock when touched indirectly. It
is also used to reduce the effect of electrical interference on electrical equipment
that affect operation of a machine or system.
PFD (Probability of Failure on Demand)
The safety parameter PFD specifies the probability of a dangerous failure.
PFH (Probability of dangerous Failure per Hour)
The safety parameter PFH specifies the probability of a dangerous failure within
one error.
PL (Performance Level)
The Performance Level PL specifies the capacity of safety devices to execute a
safety function under foreseeable conditions.
PLC
A PLC (Programmable Logic Controller) is a device used to control a machine or
system and is programmed on a digital basis.Requirement
Event that the F I/O module causes to execute its safety function
Positively driven contacts, positively driven relays
Positively driven contacts or positively driven operation means that break
contacts and make contacts can never be opened or closed at the same time in a
contact system. It must be ensured that a contact gap of min. 0.5 mm is present
throughout the service life and in the faulted state (contact welding). Relays with
positively driving contacts are normative elementary relays according to
IEC EN 61810-1 with special additional properties based on the contact set,
whose requirements are formulated in EN 50205 (see also "Actuator").
PROFIsafe
Safety-oriented data communication via the standard PROFIBUS or PROFINET
(black channel). A distinction is made between V1 mode and V2 mode.
Manual
Version 1.4.2, valid from HW/SW Version 01/02
750-667/000-003 4FDI/4FDO 24V/2A PROFIsafe V2 iPar
WAGO-I/O-SYSTEM 750