
Chapter
6
Operating Instructions
UE 440/470
52
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
8 010 432/P097/14-03-05
Electrical installation
6.2.8
Machine-cycle contacts
For PSDI mode, the machine cycle contact of the machine must be connected to the
UE 470. Depending on the PSDI mode, the UE 470 can evaluate various contacts, some of
which are mandatory (Tab. 15).
The signals of the machine cycle contacts BDC and TDC are allowed to briefly overlap one
another. BDC must always fall away before TDC.
Configured function
Top dead centre
contact (TDC)
Bottom dead
centre contact
(BDC)
Overrun
monitoring (SCC)
contact
PSDI mode with restart
interlock
(optional)
(optional)
PSDI mode without restart
interlock
(optional)
(optional)
PSDI mode Alternative
("Sweden Mode")
(optional)
(optional)
Eccentric press mode
(optional)
Overrun monitoring
(optional)
You must ensure that the machine cycle contacts meet the following criteria:
Machine cycle
contact
Criteria
TDC
$
The contact is normally closed.
$
The contact must be open for at least 100 ms before reaching the
top dead centre.
$
The contact must be closed again at the top dead centre.
BDC
$
Contact is implemented with one or two 1-channel NO contacts.
$
At the end of the dangerous movement, the contact must be closed.
$
After the TDC has opened, the contact can be opened again.
$
The contact must be opened again before the TDC is closed.
SCC
$
The contact is normally open.
$
The contact must be closed when the machine is restarted.
$
The contact must be closed when the machine is restarted.
$
The contact may be opened shortly after the machine is restarted.
In accordance with Standard EN 963, we recommend implementing the machine cycle
contact BDC with two 1-channel NO contacts.
Tab. 15: Necessary machine
cycle contacts
Fig. 21: Connection of the
machine cycle contacts
Tab. 16: Criteria for
connecting the machine cycle
contact
Recommendation
SCC
TDC
BDC