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TB074 Rev1 Adding Additional E Stop Buttons
Overview
This document describes how to properly add additional E stop buttons to a machine with M15 M39 or M400
controls
Theory of E stop Circuit Operation
The E stop button is actually a double pole normally closed switch that locks into an open state when
pressed It operates as a fail safe on two separate circuits The first job of the E stop switch is to notify the
PLC that the E stop circuit has been tripped The PLC notifies the operator of this action via a message and
then shuts down the servo drive spindle coolant etc and cancels the current job The second circuit opens
the power to the E STOP contactor which drops out the drive power spindle and coolant contactors and
turns off the servo drive thus shutting the machine down The redundancy of these systems makes for safer
operation and both are needed on any installed E stop buttons
If a Centroid qualified technician does not do the following work your warranty may be void
Connecting on a M400
The diagram below shows the connection of E Stop switches on a M400/M400S
Connecting on a M39
The diagram below shows the connection of a 2nd E Stop on a M39
Connecting on an M39S
The diagram below shows the connection of a 2nd E Stop on a M39S
Connecting on an M15
The diagram below shows the connection of a 2nd E Stop on a M15 9/M15 10
Document History
Rev1 Created on 1999 08 16