11
Trace Mode
View Data Mode
Selecting any other operating mode terminates View Status Mode.
In Trace Mode, the unit collects and stores all or selected bus traffic with
PRE or POST Trace triggering.
Trace Mode is entered by pressing the PRE-TRIG or POST-TRIG key on
the unit’s front panel. All previously collected data is erased from the
monitor’s internal storage. Bus traffic to one or all slave devices is
collected in accordance with the current Address Select Mode defined
above.
Pressing the PRE-TRIG key instructs the unit to start collecting bus traffic
upon receiving a trigger signal. Pressing the PRE-TRIG key again, or a
High-to Low transition on the External Trigger line will trigger data
collection. Once started, PRE-TRIG data collection continues until the
monitor’s internal trace buffer is full, or another operating mode is
selected.
Pressing the POST-TRIG key instructs the unit to start collecting bus
traffic immediately. Once started, POST-TRIG data collection continues
until a High-to-Low transition is detected on the External Trigger line, or
another operating mode is selected. Once the trace buffer is full, POST-
TRIG tracing continues collecting data by overwriting the oldest stored
data with the newest.
Selecting any other operating mode terminates Trace Mode.
View Data Mode displays data captured during the last trace of bus
activity. Displayed information includes:
• Number of Messages : Bytes Captured
• Start/Stop Events
• Message Number and Message Byte Number
• Message Destination Slave Address
• Read/Write Requests
