Cattron Safe-E-Stop, Руководство пользователя

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Version 17
Safe-E-
Stop™
User Guide
8. MSD
8.1 MSD Overview
The MSD provides the physical link into the machine’s hard-wired E-Stop system. Its E-Stop Safety Relays are
wired in series with this circuit.
The PSDs are dynamically linked to the MSD on an as-needed basis.
A controlled process must be in place to ensure that PSD users verify that they have linked to the MSD when
joining and when leaving have unlinked from the MSD.
Remember that the PSD has distinct and clear operator feedback to show if it is UNLINKED or LINKED. Provided
the user is correctly trained and aware, there should be low likelihood that an operator has failed to link yet
believes that they are linked. Additional confirmation may be obtained by having a PLC monitor the Ethernet port
data and turn on a lamp or buzzer by the machine when any PSD green button is pressed. This can be used as a
final confirmation that the PSD is on and linked to that machine.
NOTE 1 : The MSD does not need a PSD to be connected in order to keep its E-Stop Safety Relays closed; as
long as power is connected to the MSD and it has no faults, these relays are held closed and the hard-
wired E-Stop circuit is maintained; only the COMM LOSS relays will be open without a PSD connected.
NOTE 2 : The COMM LOSS relays are an automatic function and have a safety rating of SIL3. The COMM LOSS
relays are a positive indication that at least one PSD is linked and that none of those PSDs are in a
state of COMM LOSS.
NOTE 3 : The E-Stop relays are triggered by human action (the PSD E-Stop switch) and so are not an automatic
function; however, from the point of being triggered (E-Stop switch pressed by the user) the system has
a SIL3 performance level.
NOTE 4 : "If the machine will at times be used without any of the Safe-E-Stop PSDs in use the MSD COMM
LOSS relays will be open; therefore the COMM LOSS relays cannot be wired in series with the E-Stop
relays because the hard-wired machine E-Stop circuit will never be closed; therefore, if the COMM
LOSS relays are required they would either a) need an override switch, b) not be used or c) used to
alter operating mode by a PLC."
NOTE 5 : When one or more PSDs are linked the E-Stop and COMM LOSS relays require good communications
to stay in their closed state; a COMM LOSS will be triggered by any PSD leaving the operating range or
RF interference corrupting or blocking the RF signal.