National Instruments 320682C

Chapter 2 Formatting and I/O Library

short int instr_buf[100];

short int prog_buf[100];

status = ibrd (ud, instr_buf, 200);

Scan (instr_buf, "%100d[b2o01]>%100d", prog_buf);

If, instead, your GPIB instrument sends two-byte binary data in Motorola byte order,

the Scan function should appear as follows.

Scan (instr_buf, "%100d[b2o10]>%100d", prog_buf);

In either case, the o modifier is used only on the buffer containing the raw data from

the instrument (instr_buf). LabWindows/CVI will ensure that the program buffer

(prog_buf) is in the proper byte order for the host processor.

Note: When using both the bn and on modifiers on an integer specifier, the bn modifier

must be first.

Scanning Floating-Point Modifiers (%f)

bn Specify Length. The b floating-point modifier specifies the length of the

floating-point argument, or the length of an individual array element, in bytes. The

default length is 8 B; therefore, double-precision values do not need this modifier.

Single-precision floating-point values are indicated by b4. 8 and 4 are the only valid

values for

in Specify Array Offset. You can use the i floating-point modifier to specify an offset

within a floating-point array argument. It indicates the location within the array

where processing is to begin.

is the zero-based index of the first element to process.

Thus, %10f[i2] applied to a source floating-point array reads the 10 floating-point

values from the third through the twelfth elements of the array. The i modifier is

valid only if rep is present. If you use the i modifier with the z modifier, then n is

in terms of bytes.

zTreat String as Floating Point. The z floating-point modifier indicates that the data

type of the corresponding argument is a string. Nevertheless, the data in the string is

treated as a floating-point array. The z modifier is valid only if rep is present.

wn Specify String Size. The w floating-point modifier specifies the exact number of

bytes occupied by a string representation of the floating-point argument, in the event

that the value is converted from a string format. You can enter any non-negative

value here. If

is less than the number of digits required to represent the

floating-point number, an asterisk (*) will be inserted into the string to signify an

overflow. The default for

is zero, which indicates that the value can occupy

whatever space is necessary.

pn Specify Precision. The p floating-point modifier specifies the number of digits to the

right of the decimal point in a string representation of the floating-point number.

Significant digits may be lost in attempting to conform to the precision specification.