User Manual

TMCM-1140 Hardware Manual (Rev. 1.01 / 2012-JUL-27) 12
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3.2.2.1 Digital Inputs IN_0, IN_1, IN_2
The eight pin connector of the TMCM-1140 provides three multipurpose digital inputs IN_0, IN_1 and
IN_2.
All three inputs accept up to +24V input signals. They are protected against these higher voltages using
voltage resistor dividers together with limiting diodes against voltages below 0V (GND) and above +3.3V
DC (see figure below).
+3.3V
IN_0
IN_1
IN_2
microcontroller (all)
and TMC429 (IN_0, IN_1)
10k
22k
1nf
GND
GND GND
common switch for all
three digital inputs
1k
+5V
Figure 3.7 General purpose inputs (simplified input circuit)
Refer to the TMCM-1140 TMCL Firmware Manual (SIO command) for further information about switching
the pull-up resistors for all digital inputs on / off.
The three digital inputs have alternate functionality depending on configuration in software. The
following functions are available:
Label
(pin)
Default function
Alternate function 1
Alternate function 2
IN_0 (6)
General purpose
digital input
STOP_L - left stop switch input,
connected to processor and
TMC429 REF input (supporting
left stop functionality in
hardware)
ENC_A - external incremental
encoder input channel A,
connected to processor encoder
counter input
IN_1 (7)
General purpose
digital input
STOP_R - right stop switch input,
connected to processor and
TMC429 REF input (supporting
right stop switch functionality in
hardware)
ENC_B - external incremental
encoder input channel B,
connected to processor encoder
counter input
IN_2 (8)
General purpose
digital input
HOME - home switch input,
connected to processor
ENC_N - external incremental
encoder input index / zero
channel, connected to processor
interrupt input
Table 3.7 Multipurpose inputs / alternate functions
All three digital inputs are connected to the on-board processor and can be used as general purpose
digital inputs (default).