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Version 17
Safe-E-
Stop™
User Guide
Appendix H: Safety Manual for Safe-E-Stop
Functions
The Safe-E-Stop product has been designed to provide a wireless emergency stop function. Because it is a
wireless system, any loss of communication between the machine safety device (MSD) and any of the linked
personal safety devices (PSDs) will result in the machine stopping.
The communication loss function is controlled by the MSD and ensures that if communication with one of the
linked PSDs is lost for more than 2 seconds, the MSD will open all of its safety relays. This safety function has a
safety performance level of SIL3 according to IEC61508:2010, vol 1-7.
The emergency stop function is implemented between any linked PSD and the MSD. The emergency stop
function is not fully automatic; it is initiated when an operator presses the emergency stop switch. The design of
the system from this point to the opening of the E-Stop safety relays of the MSD has been designed to the
Systematic Capability of 3 as per IEC61508:2010, vol 1-7.
Once the E-Stop event is triggered, the stop function has a safety performance level of SIL3 according to
IEC61508:2010 vol 1-7.
Failure Modes
PSD
Any failure of the PSD will lead to the PSD transitioning into a safe state. In such a safe state, the PSD will
terminate all wireless communications, causing the MSD to detect a communication loss and open all the safety
relays (E-Stop and COMM LOSS). This will bring the machine to a safe state. The display on the PSD will show
ERROR 1 and the error LED will flash.
MSD
Any failure of the MSD will lead to the MSD transitioning into a safe state. In such a safe state, the MSD will open
all safety relays and stop all wireless communication with the PSDs. The display on the MSD will show ERROR 1
and the error LED will flash.
Operational Constraints
The PSD is a personal safety device. It is the responsibility of the operator/user to verify that the PSD is linked. In
an environment where multiple systems are in use, the operators need to be trained to verify that the correct PSD
is in use.
Several methods are suggested to help the operator select the right PSD:
● Clear identification of the machine under control that corresponds with the configuration labels on the
PSD side labels.
● A color code such as the colored logo label option or the different colored PSD option.
● By connecting a PLC using the Ethernet interface, the PLC could provide some indication of each PSD
that is connected by using the green button on the PSD; the PLC could also provide a visual or audible
indication that it is acting on the intended machine.
