User Documentation
4 System description of safe power-feed modules
15u-remote IP20 modules for functional safety manual 1484600000/07/11.2020
This chapter contains product-specic informa-
tion and notes about the use of safe power-feed
modules. Please also observe the system descrip-
tion in the u-remote manual document umber
1432790000)
The PF-O-xDI-SIL modules are controlled using con-
tact-based safety transducers and/or safety transducers with
OSSD outputs.
Each PF-O-xDI-SIL module safely switches off all fol-
lowing modules that are supplied by the output current path
and thus creates a safety segment. A survey of the switch-
able modules is shown at the end of this section. The safety
segment extends either to the next PF-O module or to the
end of the station. A safety-related input circuit together with
pulsed inputs is used for detecting broken wires and short
circuits.
Three types of safe power-feed modules are available in the
u-remote system:
– UR20-PF-O-1DI-SIL (one safe input)
– UR20-PF-O-2DI-SIL (two safe inputs)
– UR20-PF-O-2DI-DELAY-SIL (two safe inputs, delayed
switching off possible)
Thereby the following safety functions can be implemented:
– Up to two dual-channel safety circuits (AND linked), e.g.
for emergency stop switch, safety door contacts and
safety light curtains
– A range of output modules within a u-remote station is
safely supplied with power via the switched 24VSafe
output.
– PF-O-xDI-SIL modules can be cascaded.
Safety function
The safety function of the safe power-feed modules is
that the safe output “24VSafe” is being switched accord-
ing to the informations of the inputs (Type3 according to
EN61131-2, N-switching respectively). The safe status is
“24V switched off” (current path for outputs and the output
“24V Safe” is switched off).
Safe power-feed module UR20-PF-O-1DI-SIL
Safe power-feed module UR20-PF-O-2DI-SIL and UR20-PF-O-2DI-DELAY-SIL
4 System description of safe power-feed modules