Teledyne LeCroy PXA125 - Manual (Page 195)

User Manual PXA125
Programming Reference 4-77
•
will select the STAR trigger module. Select this option only if you have a STAR module in your
system
SEQuence:ADVance:SOURce?
Response and default
The PXA125 will return EXT, INT, TTLT, or STAR depending on the present trigger advance source
setting. Default value is EXT.
SEQuence:DEFine ,,<#_repeat>,
Purpose
This command will define sequence steps and their associated advance mode.
•
will define the link number
•
will select the segment for the above link
•
<#_repeat> will define how many times the selected segment will loop
•
will assign the mixed mode bits for this sequence step. “0” programs normal advance, “1”
programs trigger advance. Step with a “0” bit assigned to it will advance automatically to the next step. If
“1” is assigned to a step, the instrument will generate this step and its associated number of repeats
continuously and only a valid trigger signal will advance this step to the next step. Note that the
parameter has no affect when the sequence advance mode is set to SING.
To understand better the way the switch affects a sequence, consider the following sequence
setting:
SEQ:DEF 1,1,1,0
(Step 1 = segment 1, no loops, mode 0)
SEQ:DEF 2,2,1,1
(Step 2 = segment 2, no loops, mode 1)
SEQ:DEF 3,3,10,1
(Step 3 = segment 3, 10 loops, mode 1)
SEQ:DEF 4,4,1,0
(Step 4 = segment 4, no loops, mode 0)
After selecting the sequence mode, the generator will generate segment 1 and automatically advance to
segment 2. It will continue to generate segment 2 until a valid trigger is received. After it has received a
trigger, the generator will complete segment 2 and advance to segment 3. It will continue to generate and
loop segment 2 until a valid trigger is received. After it has received a trigger, the generator will complete 10
loops of segment 3 and will advance to segment 4. From segment 4 the generator will automatically advance
to the beginning of the sequence and will repeat the above.
NOTE
Although trigger signals are used to advance mixed mode, the mixed mode operates in
continuous mode only. The parameter will be ignored if you will use SING as
advance mode for the sequence table.
TIP
Every time you use the SEQ:DEF command while your PXA125 is in sequenced
operating mode, the instrument attempts to rebuild the sequence table and restart the
sequence. Therefore, sending this command in sequenced mode will slow the
programming process and the operation of the generator. Using the SEQ:DEF
command in FIX or USER mode will greatly speed up programming time.
SEQuence:DELete:ALL
Purpose
This command will erase the sequence table.