Models 707B and 708B Switching Matrix Reference Manual
Section 7: Command reference
707B-901-01 Rev. A / August 2010
7-59
Usage
triggerMode = digio.trigger[N].mode
digio.trigger[N].mode = triggerMode
triggerMode
The trigger mode; see Details for values.
N
Digital I/O trigger line (1 to 14).
Details
Set
tmode
to one of the following values:
Trigger mode values
triggerMode
Description
digio.TRIG_BYPASS
or
0
Allows direct control of the line.
digio.TRIG_FALLING
or
1
Detects falling-edge triggers as input; asserts a TTL-low
pulse for output.
digio.TRIG_RISING
or
2
If the programmed state of the line is high, the
digio.TRIG_RISING
mode behaves similar to
digio.TRIG_RISINGA
. If the programmed state of the line
is low, the
digio.TRIG_RISING
mode behaves similar to
digio.TRIG_RISINGM
. This setting should only be used if
necessary for compatibility with other Keithley Instruments
products.
digio.TRIG_EITHER
or
3
Detects rising- or falling-edge triggers as input. Asserts a
TTL-low pulse for output.
digio.TRIG_SYNCHRONOUSA
or
4
Detects the falling-edge input triggers and automatically
latches and drives the trigger line low. Asserting the output
trigger releases the latched line.
digio.TRIG_SYNCHRONOUS
or
5
Detects the falling-edge input triggers and automatically
latches and drives the trigger line low. Asserts a TTL-low
pulse as an output trigger.
digio.TRIG_SYNCHRONOUSM
or
6
Detects rising-edge triggers as input. Asserts a TTL-low
pulse for output.
digio.TRIG_RISINGA
or
7
Detects rising-edge triggers as input. Asserts a TTL-low
pulse for output.
digio.TRIG_RISINGM
or
8
Asserts a TTL-high pulse for output. Input edge detection is
not possible in this mode.
When programmed to any mode except
digio.TRIG_BYPASS
, the output state of the I/O line is controlled by
the trigger logic, and the user-specified output state of the line is ignored.
digio.TRIG_SYNCHRONOUS
is provided for compatibility with older firmware. Either
digio.TRIG_SYNCHRONOUSA
or
digio.TRIG_SYNCHRONOUSM
should be used instead.
When reading the trigger mode,
tmode
is returned as a number.
To control the line state, use
digio.TRIG_BYPASS
with the
digio.writebit()
and the
digio.writeport()
commands.
Example
digio.trigger[4].mode = 2
Sets the trigger mode for I/O Line 4 to
digio.TRIG_RISING
.