Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 338)

III. COMMAND REFERENCES - 15. Command References 15B. Driver488/SUB, W31, W95, & WNT
Personal488 User’s Manual, Rev. 3.0 III-323
always refer to an I/O adapter, and the forceAddr flag is ignored. Thus, EnterMore is equivalent to
Enter , and EnterNMore is equivalent to EnterN .
EnterI (Controller Mode)
Driver488/W31 (Visual Basic only)
EnterXI
SYNTAX EnterXI (ByVal devHandle% ,data%, ByVal count&, ByVal
forceAddr%, Term As terms, ByVal async%, compStat%)As Long
devHandle% refers to either an IEEE 488 interface or an external device.
data% is the first element in an integer array into which the data is read.
count& is the number of characters to read.
forceAddr% is used to specify whether the addressing control bytes are to be
issued for each EnterXI command.
term is a pointer to a terminator structure that is used to set up the input
terminators. If term is set to 0 , the default terminator is used.
async% is a flag that allows asynchronous data transfer.
compStat% is a pointer to an integer containing completion status information.
RETURNS -1 if error,
otherwise the number of bytes transferred. The memory buffer
pointed to by the data parameter is filled in with the
information read from the device.
MODE CA
BUS STATES ATN
•UNL, MLA, TAG, *ATN, data (With external device handle)
*ATN, data (With interface handle)
SEE ALSO Output, Term, Buffered, EOL (Sub-Chapter 15A)
EXAMPLE term.EOI = TRUE
term.nChar = 1
term.EightBits = TRUE
term.term1 = &HA
bytecount=EnterXI(timer,data%(0),1024,0,term,1,stat)
These EnterI commands for Visual Basic are identical to the standard Enter commands with the
exception of the return values being placed in integer variables rather than string variables.
The EnterXI command reads data from the I/O adapter. If an external device is specified, then
Driver488 is addressed to Listen, and that device is addressed to Talk. If an interface is specified, then
Driver488 must already be configured to receive data and the external device must be configured to
Talk, either as a result of an immediately preceding
EnterXI command or as a result of one of the
Send commands. EnterXI terminates reception on either the specified count of bytes transferred, or
the specified or default terminator being detected. Terminator characters, if any, are stripped from the
received data before the
EnterXI command returns to the calling application.
The forceAddr% flag is used to specify whether the addressing control bytes are to be issued for each
EnterXI command. If the device handle refers to an I/O adapter, then forceAddr% has no effect and
command bytes are not sent. For an external device, if forceAddr% is TRUE then Driver488 always
sends the UNL , MLA , and TAG command bytes. If forceAddr% is FALSE , then Driver488 compares the
current device with the previous device that used that interface adapter board for an EnterXI
command. If they are the same, then no command bytes are sent. If they are different, then EnterXI
acts as if the forceAddr% flag were TRUE and sends the command bytes. The forceAddr% flag is
usually set TRUE for the first transfer of data from a device, and then set FALSE for additional transfers
from the same block of data from that device.
Additional EnterI Functions