Appendix A
58
HA0237T Rev E Aug 2014
A.3.1
Trigger Out (Digital Output)
The digital output (AxisOut) can continuously sink over 100 mA and source 4 mA from
the pull up resistor to 5V. The diode in series with the pull up resistor allows loads
powered from up to 24VDC to be switched. The FET driver is internally protected from
shorts up to 30 V.
Fig. A.4 Digital Output Schematic
Please see the APTServer helpfile for details on software calls used to control these
logic IO.
A.3.2
Trigger In (Digital Input)
The digital input (AxisIn) circuit accepts signals in the range 0 to 24 V and has TTL
compatible, Schmidt trigger thresholds. It has a pull up to 5V to allow direct interfacing
to open collector souces without the need for an external pull up resistor and a 13 kHz
R-C low pass filter to reject noise.
Fig. A.5 Digital Input Schematic
5V
1.0k
AxisOut
5V
5V
4.7k
22k
560p
AxisIn
74ACT14