61
K-Cube Position Aligner
Trigger Settings
The mode for each trigger port is set in the appropriate
Trigger Mode
parameters as
follows:
Disabled
- The trigger IO is disabled. Selecting this option effectively results in the
port returning to its default digital input configuration.
TrigIn - GPI
- General purpose logic input. Other than being able to read the logic
state of port there is no other functionality associated with it. The state of the port
is returned in the periodic status update messages, or can be read by using the
GetStatusBits method. In this mode the
Triggering Polarity
setting has no effect;
the logic state of the input is returned as it is present on the port without inversion.
TrigIn - Loop Open/Close:
In this mode the port can be used to togg le the
operating mode of the controller between open loop and closed loop modes. If the
trigger polarity is selected to be "Active High", the operating mode toggles on the
rising edge (LOW to HIGH transition) of the signal present on the TRIG input.
Conversely, with "Active Low", the toggle takes place on the falling edge (HIGH to
LOW transition).
TrigOut - GPO
- In this operating mode the TRIG port functions as a simple digital
output. The logic state of the output can be set using the SetGetDigOPs method.
Other than being able to read the logic state of port there is no other functionality
associated with it. The logic state of the output can be inverted by setting the
Triggering Polarity
parameter to "Low"; with this option selected the state of the
output will be the opposite of the corresponding bit setting in the software call. The
default state of the output in this mode is also the opposite of the option selected
as the
Triggering Polarity
.
TrigOut - SUM
- The state of the TRIG port is asserted depending on whether the
SUM signal coming from the position sensor is inside the limits specified in the
Trig Sum Min
and
Trig Sum Max
parameters. If SUM is within the limits, the state
will be th e logic state selected in
Triggering Polarity
and conversely if it falls
outside these limits, it will assume the opposite logic state. This mode can be used
to detect the presence or absence of light falling on the position sensor; or that the
optical power is within the expected limits. This option might be useful to signal a
condition required for normal operation as under normal operating conditions the
optical power is often expected to remain fairly constant. The
Sum Minimum
and
Sum Maximum
parameters are specified as a percentage of full scale, in the range
1% to 99%.
Warning
Do not drive the TRIG ports from any voltage source that can produce an
output in excess of the normal 0 to 5 Volt logic level range. In any case
the voltage at the TRIG ports must be limited to -0.25 to +5.25 Volts.
