Denso Power Net Terminal BHT-7500 Especificações descarregar pdf (Página 146)

100

101

Chapter 8. Files

137

8.2.3 Structure of Data Files

■ Record

A data file is made up of a maximum of 32767 records. A record is a set of data in a data

file and its format is defined by the FIELD statement. The maximum length of a record is

255 bytes including the number of the character count bytes* (= the number of the fields).

* When transferring data files, the BHT-protocol/BHT-Ir protocol automatically prefixes a character

count byte in binary format to each data field.

■ Field

A record is made up of 1 to 16 fields. Data within the fields will be treated as character

(ASCII) data.

Each field precedes a character count byte in binary format, as described above. Including

that one byte, the maximum length of a field is 255 bytes.

The following

FIELD statement defines a record which occupies a 28-byte memory area

(13 + 5 + 10 bytes) for data and a 3-byte memory area for three character count bytes.

Totally, this record occupies not a 28-byte area but a 31-byte area in the memory.

FIELD #2,13 AS bardat$,5 AS keydat$,10 AS dt$

’1+13+1+5+1+10=31 bytes

* When a data file is transmitted according to the BHT-protocol, the following conditions

should be also satisfied:

• The maximum length of a field is 254 bytes (99 bytes in the BHT-3000/BHT-4000)

excluding a character count byte.

8.2.4 Data File Management by Directory Informa-

tion

The Interpreter manages data files using the directory information stored in the system area of

the memory.

The directory information, for example, contains the following:

filename.extension

Information of Each Field (Field length)

Number of Written Records

Maximum Number of Registrable Records

• Number of Written Records

Means the number of records already written in a data file, which the LOF function can

return.

If no record number is specified in the

PUT statement, the Interpreter automatically

assigns a number of (the current written record number + 1) to the record.

PUT #1

1 2 ... 141 142 143 144 145 146 147 148 149 150 151 ... 559 560

Comentários a estes Manuais

Sem comentários

Denso Power Net Terminal BHT-7500 Especificações Página 146

Comentários a estes Manuais

Manuais e produtos relacionados com Leitores de códigos de barras Denso Power Net Terminal BHT-7500