Ibeos, Table 4a.5 - data transfer termination method – National Instruments GPIB-PC User Manual

Page 101

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BASICA/QuickBASIC GPIB-PC Function Calls

Section Four A

GPIB-PC User Manual

4A-26

©National Instruments Corp.

BASICA/QuickBASIC

BASICA/QuickBASIC

IBEOS

IBEOS

Purpose:

Change or disable end-of-string termination mode

Format:

CALL IBEOS (BD%,V%)

Remarks:

BD%

specifies a device or an interface board.

V%

specifies

the EOS character and the data transfer termination method
according to Table 4A.5.

IBEOS

is needed only to alter the

value from its configuration setting.

The assignment made by this function remains in effect
until

IBEOS

is called again, the

IBONL

or

IBFIND

function is called, or the system is rebooted.

When

IBEOS

is called and an error does not occur, the

previous value of

V%

is stored in

IBERR%

.

Table 4A.5 - Data Transfer Termination Method

Method

Value of V%

High Byte Low Byte

A. Terminate read when EOS

00000100

EOS

is detected

B. Set EOI with EOS on write

00001000

EOS

function

C. Compare all 8 bits of EOS

00010000

EOS

byte rather than low 7 bits
(all read and write functions)

Methods A and C determine how read operations terminate.
If Method A alone is chosen, reads terminate when the low
7 bits of the byte that is read match the low 7 bits of the
EOS character. If Methods A and C are chosen, a full 8-bit
comparison is used.

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