Exfo FLS-2200 Broadband Source Manual de usuario descargar pdf (Pagina 114)

Data Types

106 FLS-2200

Applicable Data Types for Output—IEEE 488.2

 <DEFINITE LENGTH ARBITRARY BLOCK RESPONSE DATA>

This data type is used by a device to return blocks of 8-bit binary

information with a fixed and predetermined length.

The actual length of the retrieved data has the following structure:

 The first byte contains the # character.

 The byte that immediately follows contains the number of

subsequent bytes that you have to check to know the total length.

For example, if you receive this response (here, values are expressed

in decimal instead of binary for easier readability):

# 2 1 3 7 6 8 9 2 ...

The byte that immediately follows the # contains 2, which means that

you have to read the two following bytes to know the length (in bytes)

of the retrieved data. The bytes indicate 1 and 3. The length will then

be 13 bytes. The actual response will begin at byte number 5, in this

case.

Examples: #14<DAB><DAB><DAB><DAB>,

#3004<DAB><DAB><DAB><DAB>

where “<DAB>” stands for data byte

<non-zero

digit>

<digit>

<8-bit data

byte>

1 2 ... 109 110 111 112 113 114 115 116 117 118 119 ... 182 183

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Exfo FLS-2200 Broadband Source Manual de usuario Pagina 114