IDEC SG4 Type 4 Finger & Hand - Manual (Page 64)

SG4-B Series Instruction Manual
60
EMITTER: unit emitting infrared beams, consisting of a set of optically-
synchronised LEDs. The emitting unit, combined with the receiving unit
(installed in the opposite position), generates an optical “curtain”, i.e.
the detecting area.
EXTERNAL DEVICE MONITORING (EDM): device used by the ESPE
to monitor the status of the external command devices.
FINAL SWITCHING DEVICE (FSD): part of the control system
involving machine safety conditions. It breaks the circuit to the
machine primary control element (MPCE) when the output signal
switching device (OSSD) becomes inactive.
FORCE-GUIDED CONTACTS: Contacts can be guided forcibly when
they are connected mechanically so that they can switch
simultaneously, when the input stage is active.
If one contact of the series remains “hanged”, no other relay contact is
able to move.
This function allows the control of the EDM status.
MACHINE OPERATOR: qualified person allowed to use the machine.
MACHINE PRIMARY CONTROL ELEMENT (MPCE): electrically-
powered element having the direct control of machine regular
operation so as to be the last element, in order of time, to operate
when the machine has to be enabled or blocked.
MIN. INSTALLATION DISTANCE: min. distance necessary to allow
machine dangerous moving parts to completely stop before the
operator can reach the nearest dangerous point. This distance shall be
measured from the middle point of the detecting area to the nearest
dangerous point. Factors affecting min. installation distance value are
machine stop time, total safety system response time and light curtain
resolution.
N.O.: normally opened
N.C.: normally closed
OFF STATUS: status when the output circuit is interrupted and does
not allow current stream.
ON STATUS: status when the output circuit is operational and allows
current stream.