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Version 17
Safe-E-
Stop™
User Guide
6.
PSD
6.1 PSD Overview
PSDs can be considered a set of wireless E-Stop switches that are dynamically linked to the MSD on an as-
needed basis. 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.
The MSD provides the physical link into the hard-wired E-Stop system of the machine. Its E-Stop Safety Relays
are wired in series with this circuit and reflecting the status of the PSDs E-Stop switches.
Up to five out of a total of fifteen PSDs can be linked to an MSD at any one time.
If a PSD is linked to the MSD, the MSD E-Stop Safety Relays are then subject to additional rules relating to the
RF communication link between the PSD and MSD, as well as the PSD E-Stop switch remaining out:
● Corruption / loss of the RF link or an E-Stop switch being pressed will open the MSD E-Stop
relays.
● Corruption / loss of the RF link will also open the COMM LOSS relays.
● A controlled process is in place to enable PSDs to link and unlink from the MSD.
6.2 PSD Status Indications
PSDs have audio, visual (LED and LCD), and haptic (vibration) warning systems to indicate the current status,
such as normal operation, low battery, low RF signal, etc.
Figure 3: PSD Indications