Instruction manual

Connection box C-BOX 300

C-BOX data collection using minimum flow control

ubject to reasonable modifications due to technical advances. Copyright Pepperl+Fuchs, Printed in Germany

epperl+Fuchs Group • Tel.: Germany (06 21) 7 76-0 • USA (330) 4 25 35 55 • Singapore 7 79 90 91 • Internet http://www.pepperl-fuchs.com

Date od issue 07/25/2003

Application data areas are to be formatted as follows:

All other bytes are insignificantly.

6 C-BOX data collection using minimum flow control

Some examples of the Datalogic PROFIBUS Driver (DPD) managing C-BOX are

described for the following cases. These are simplified examples using minimum flow

control where:

• fragmentation/reassembling are not used:

the precondition for this is that the input area is large enough (INPUT AREA

LENGTH >= barcode string length + 4, see definitions below);

6.1 Definitions

• INPUT AREA is one of the two PROFIBUS DP EXCHANGE AREAS. More pre-

cisely it is the one that is updated by the C-BOX Slave and read by the Master

(generally a PC or a PLC);

• OUTPUT AREA is one of the two PROFIBUS DP EXCHANGE AREAS. More pre-

cisely it is the one that is updated by the Master and read by the C-BOX Slave

station;

• INPUT AREA LENGTH length of the input area (must be configured at the Master

side with a value greater than or equal to 8);

• OUTPUT AREA LENGTH length of the output area (must be configured at the

Master side with a value greater than or equal to 8);

• DPD overhead bytes, these are the first four bytes of both the input and output

areas. These bytes are reserved for DPD information. It is composed of:

1. control byte

2. station address byte, it corresponds to the C-BOX station address;

3. SAP byte

4. length byte, in practice it is the significant length of the barcode string;

• Barcode string, all the characters that belong to a barcode event (i.e. the same

sequence of characters that would be sent to the asynchronous serial line, if an

asynchronous line were used to send barcode data instead of PROFIBUS). This

string will be inserted in the input area starting from the fifth byte.

Request Format

Command byte 4 byte 5

Flush data buffer '[' 'F'

Response Format depending on the Retcode

Retcode byte 4 byte 5

Command accepted 'A' ' '

Command rejected 'C' ' '