.  Hill Country Research Innovations in Telecommunication and Automation   Broken Tool Detector MS-5 Data Sheet

In its normal state (plunger out) the signal line provides a logical "1" (24V).  Activating the plunger causes the
potential at the signal line to drop to near zero Volt, supplying a logical "0" to the digital input card of the CNC
machine.

A cable fault would produce the same result as a defective work piece, the signal line goes to "0"and stops the machine (fail safe).

If the unit is to be operated without the CNC machine, a 3 kOhm load resistor from the signal line to ground is required.  Without the resistor, the output voltage might not change when the plunger is activated (depends on impedance of test set up).
 

Mechanical specifications (approx.):

Length:                       92 mm (3.62'') with plunger, 80 mm (3.15'') without
Diameter:                    9.5 mm (0.37'')
Plunger travel:            12 mm (0.47''), 10 mm (0.39'') past switching point
Cable length:              4 m ( 13.2'), teflon

Electrical specifications:

Supply voltage:          24 V DC
Supply current:          < 30 mA
Signal line load:         2- 5 kOhm

Connections:

Red/white                  +24 V
Blue/white                 ground
White                        signal out
 
 

Not sure how to hook it up?   Here is a  schematic.