Manual

C HAPTER T WO : Control by GPIB
WM-RCM-E Rev D ISSUED: February 2005 19
MAKE SIMPLE TRANSFERS
For a large number of remote control operations, it is sufficient to use just three different subroutines
(IBFIND, IBRD and IBWRT) provided by National Instruments. The following complete program reads the
timebase setting of the X-Stream DSO and displays it on the terminal:
GPIB:
This line holds the INCLUDE for the GPIB routines
Find: DEV$ = “DEV4” ‘ Because the DSO has been set at
address 4.
CALL IBFIND (DEV$, SCOPE%) ‘ Find the DSO: label it “SCOPE%”.
Send: CMD$ = “TDIV?” ‘ Make a query string about the
time base speed.
CALL IBWRT (SCOPE%, CMD$) ‘ Send the string to the DSO.
Read: CALL IBRD (SCOPE%, RD$) ‘ Read the response from the DSO.
PRINT RD$ ‘ Print the response string.
END
Explanation
GPIB: This line or lines must hold the link between the programming language and the National Instruments
GPIB functions and drivers.
Find: Open the device DEV4 and associate with it the descriptor SCOPE%. All I/O calls after that will refer
to SCOPE%. The default configuration of the GPIB handler recognizes DEV4 and associates with it a device
with the GPIB address 4.
Send: Prepare the command string TDIV? and transfer it to the oscilloscope. The command instructs the
oscilloscope to respond with the current setting of the timebase.
Read: Read the response of the oscilloscope and place it into the character string RD$.