1257 User Manual
EADS North America Defense
Advanced SCPI Operations 7-9
Test and Services, Inc.
©
2001
Arming and
Disarming the 1257
Before scanning of channels can be performed, the 1257 must be
armed. Arming is accomplished with the INITIATE command. The
syntax for the INITIATE command is:
:INITiate
:IMMediate
{ON|1|OFF|0}
:CONTinuous
{ON|1|OFF|0}
The INITIATE:IMMEDIATE command arms the 1257. This enables
the 1257 to accept new triggers and continue scanning. Each time
the INIT:IMMEDIATE command is received by the 1257, it enables
triggering for the scan list. Each time this command is received, the
number of elements which may be scanned is set to the trigger
count.
Each time the INIT:IMMEDIATE command is received, scanning
resumes from the point at which it was stopped, NOT from the
beginning of the scan list. That is, if the commands:
SCAN (@1(0:19))
TRIG:COUNT
3
TRIG:SOUR
BUS
INIT:IMMEDIATE
are executed, the 1257 will accept up to 3 triggers. After the third
trigger, scanning will be disabled since the trigger count value has
been reached. At this point, channel 2 will be closed, because it is
the third element in the scan list.
Now if a second INIT:IMMEDIATE command is received, the 1257
will accept up to 3 more triggers. The first trigger received will open
channel 2, and close channel 3.
The INIT:CONTINUOUS command also arms the 1257. This
command allows the 1257 to continuously scan through the
channels in the scan list. The 1257 will NOT stop scanning after
the number of triggers equal to the trigger count have been
received. This command effectively bypasses the trigger count
limit.
The ABORT command disarms the 1257. Once the 1257 receives
the ABOR or ABORT command, it will not perform any scan list
actions until it is rearmed by using the INIT:IMMEDIATE or
INIT:CONTINUOUS commands.
At power-up, and after executing a *RST command, the 1257 is
disarmed.
