Advantech PCLS-848-P, User Manual

Page: 22 / 106

1 6 PCLS-848-P User's Manual
The IEEE-488 procedUres and resident firmware convert your command and data
strings to specific control codes for the IEEE-488 bus controller chip. It also passes
back received data and interface status conditions to your program. Received informa-
tion may be used directly by your program and the status codes (those returned by
the procedure iestatus) may be used to determine various interface operating condi-
tions or to detect errors in the statements.
The firmware routines are located in memory at the segment decoded by the address
switch SW2 on the card. It can be located in any one of thirty-two 65,536 byte
segments in the PC’s address space. ( Segment hex 8000 to FC00 )
Please review Section 2.2.2. for firmware segment setting. The default of SW2 setting
is for segment hex D000. In most cases, this setting is all right for operation. Keep this
setting unless another add-on card occupies this memory space and cannot be
changed.
Each IEEE-488 procedure or function specifies the parameters that it must receive
from the program or the parameters that it passes back to the program. These
parameters are shown in parentheses following the procedure or function name.
The order, number and type of variables passed to the procedures and functions must
be exactly as shown at the definition for each procedure and function.
The next sections discuss the IEEE-488 procedures. Microsoft Pascal users should
skip Section 3.3. and Turbo Pascal users should skip Section 3.2.
3.2. Using the IEEE-488 Drivers for Microsoft Pascal
The IEEE-488 library procedures and functions for Microsoft Pascal (MSPGPIB.LIB
) can be thought of as an extension to the libraries that Microsoft offered, such as
PASCAL.LIB and ALTMATH.LIB.