Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 226)

Section 4C
Connecting the 4-axis Servo Module
4C-28
Figure 4C.19 shows the internal servo module circuitry that interfaces to
the touch probe connector. It is shown here to assist you in determining
whether your touch probe hardware is compatible.
Figure 4C.19
Internal Circuitry Supporting the Touch Probe
11309-I
4
3
2
1
Servo Module
470 ohm
5V common
1000 ohm
+5 V dc Encoder Power
+5V Power
probe
GND
Shield
to encoder interface
The following table indicates probing threshold voltages. Maximum Input
Threshold (critical if the control has been configured to fire on the falling
edge of the probe signal) indicates the voltage that the probe signal must
fall below to be considered as “fired”. Minimum Input Threshold (critical
if the control has been configured to fire on the rising edge of the probe
signal) indicates the voltage that the probe signal must rise above to be
considered as fired
Probe Thresholds Voltage at Threshold
Minimum Input Threshold (probe circuit) 3.06 (min)
Maximum Input Threshold (probe circuit) 2.18V dc (max)