Racal Instruments 1256E Manual page 178

Advanced SCPI Operations 8-14
A) Program the 1256 to close a channel
B) Wait/Query the 1256 to ensure the channel is closed
C) Program the DMM to take a reading
D) Program the 1256 to open a channel
With the Scan List feature, the DMM and 1256 are programmed to
trigger each other for each DMM reading. After this, sending a
trigger to the 1256 intiates the cycle of:
Close Relay, Take DMM Reading, Open Relay
automatically. When all of the desired readings have been made,
the DMM may be read to obtain the group of measurements. This
method usually results in increased measurement rate by
minimizing the command processing time of the instruments
involved.
To set up the Scan List, the programmer must:
A) Program the 1256 to define the list of channels to scan
through, using the SCAN command.
B) Program the 1256 to select an input trigger source. This input
trigger source should be the external trigger input. The
TRIGGER:SOURCE command is used to select the input
trigger.
C) Program the 1256 to generate a trigger each time a relay is
closed. The output trigger must be enabled, through the
OUTPUT:TRIGGER command.
D) Program the DMM (or other instrument) to select an output
trigger source. The output trigger source should be the input
trigger source of the 1256, as indicated in step (B) above.
E) Program the DMM to select an input trigger source. The input
trigger source should be the output trigger line of the 1256,
as indicated in step (C) above.
F) Program the DMM to select a trigger count, which sets the
number of channels to scan through.
G) Program the DMM to select the number of readings to store.
H) Send the command TRIGGER:IMMEDIATE to the 1256 to
initiate the Scan operation.
I) Repeatedly query the DMM to wait until the measurements
have completed.
J) Read the measurements from the DMM.
The commands used to program the DMM (or other instrument)
depend on the instrument being used. Consult the user
documentation of the instrument for a description of how to
perform steps (D), (E), (G), (J), and (K) above.
The remainder of this section describes how to define a scan list,
1256E User Manual
Racal Instruments © 2002