Arming And Disarming The 1256 - Racal Instruments 1256E Manual

Arming and
Disarming the 1256
Advanced SCPI Operations 8-10
Before scanning of channels can be performed, the 1256 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 1256. This enables
the 1256 to accept new triggers and continue scanning. Each time
the INIT:IMMEDIATE command is received by the 1256, 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 1256 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 from module 1 will be
closed, because it is the third element in the scan list.
Now if a second INIT:IMMEDIATE command is received, the 1256
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 1256. This
command allows the 1256 to continuously scan through the
channels in the scan list. The 1256 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 1256. Once the 1256 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 1256 is
disarmed.
The trigger and arm state diagram is shown in Figure 8-1. This
1256E User Manual
Racal Instruments © 2002