VXI VT1422A - Manual (Page 258)

256 VT1422A Command Reference Chapter 7
ARM
ARM
The ARM subsystem is only useful when the TRIGer:SOURce is set to TIMer.
With the VT1422A, when the TRIG:SOURCE is set to TIMer, an ARM event must
occur to start the timer. This can be something as simple as executing the
ARM[:IMMediate] command or it could be another event selected by
ARM:SOURCE.
Note
The ARM subsystem may only be used then the TRIGger:SOURce is TIMer. If the
TRIGger:SOURce is not TIMer and ARM:SOURce is set
to anything other than IMMediate, an Error -221,"Settings conflict" will
be generated.
The ARM command subsystem provides:
•
An immediate software ARM (ARM:IMM).
•
Selection of the ARM source (ARM:SOUR BUS | EXT | HOLD | IMM | SCP |
TTLTRG) when TRIG:SOUR is TIMer.
Figure 7-2 shows the overall logical model of the Trigger System.
Figure 7-2. Logical Trigger Model
BUS
EXTernal
HOLD
IMMediate
TTLTrg
SCP Trg
ARM
/TRI
G
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r
S
o
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T
ri
g
ge
r
S
ou
rce
S
e
lecto
r
A
rm
S
ou
rce
S
e
lec
to
r
ARM:SOURce
TRIGger:TIMer
Trigger
Timer
TIMer
Trigger
Enable
TRIGger:SOURce
Internal
Trigger Signal
Trigger
Counter
TRIGger:COUNt