National Instruments GPIB-PC - page 49

GPIB-PC Functions — Introduction Section Three
GPIB-PC User Manual 3-6 ©National Instruments Corp.
These functions are used under the following conditions:
• Program execution must proceed in parallel with GPIB I/O –
often called asynchronous operation.
• I/O is to or from a file rather than a memory buffer.
• Controller-In-Charge authority must be transferred to another
GPIB device.
• The timeout value must be changed.
• The handler must be reinitialized with respect to certain
devices.
IBRDA (bd,buf,cnt) and
IBWRTA (bd,buf,cnt)
These functions are similar to IBRD and IBWRT except that the
operation is asynchronous. This means that the function returns after
starting the I/O operation without waiting for it to complete.
When programming in BASIC, IBRDA and IBWRTA perform string
transfers. IBRDIA and IBWRTIA are available for transfers to and from
an integer array.
IBRDF (bd,buf,cnt) and
IBWRTF (bd,buf,cnt)
These functions are similar to IBRD and IBWRT except that data is read
into a file.
IBWAIT (bd,mask)
IBWAIT waits for one or more events to occur. For the IBRDA and
IBWRTA functions, the event to wait for is the completion of the
operation.
IBSTOP (bd)
IBSTOP aborts any asynchronous operation associated with the device.