Models 707B and 708B Switching Matrix Reference Manual
Section 3: Functions and features
707B-901-01 Rev. B / January 2015
3-13
For more examples of using scanning and triggering, see the Models 707B and 708B User's Manual,
section "Using a Series 2600 with your Model 707B or 708B."
Hardware trigger modes
Use the hardware trigger modes to integrate Keithley Instruments and non-Keithley instruments into
an efficient test system. The hardware synchronization lines are classic trigger lines. The Model 707B
or 708B contains 14 digital I/O lines and three TSP-Link synchronization lines that you can use for
input or output triggering. The following table provides a summary for each hardware trigger mode.
Trigger mode
Output
Input
Notes
Unasserted
Asserted
Detects
Bypass
N/A
N/A
N/A
Use the
writebit
and
writeport
commands for direct line control
Either edge
High
Low
Either
Short input pulses can cause a trigger
overrun
Falling edge
High
Low
Falling
Rising edge
N/A
N/A
N/A
•
The programmed state of the line
determines if the behavior is similar
to RisingA or RisingM
•
High similar to RisingA
•
Low similar to RisingM
Rising A
High
Low
Rising
RisingM
Low
High
None
Synchronous
High
latching
Low
Falling
•
Behaves similar to SynchronousA
•
Trigger overrun detection is disabled
•
To mirror the SynchronousA trigger
mode, set the pulse duration to 1 µs
or any small nonzero value
SynchronousA
High
latching
High
Falling
Ignores the pulse duration
SynchronousM
High
Low
Rising
Each trigger mode controls the input trigger detection and output trigger generation. The input
detector monitors for and detects all edges, even if the node that generates the output trigger causes
the edge.
A trigger overrun generates if an input trigger is received before the previous input trigger processes.
To determine if a trigger overrun has occurred, reference the trigger overrun attributes.
For additional information on the hardware trigger modes, see TSP commands.
To have direct control of the line state, use the bypass trigger mode.