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

Pepperl+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

6.2 What to Implement

As a result of the previous definitions we have that:

1. C-BOX toggles the first bit of the first byte of the input area whenever a new

barcode event is inserted in the input area; this will happen if and only if the

previous barcode event had been acknowledged by the Master. If not, data are

kept in an internal queue and will be sent only after an explicit acknowledge is

received;

2. A Master PLC/PC toggles the first bit of the first byte of the output area in order

to acknowledge the reception of the new barcode.

3. The second bytes of both the input and output areas are equal to the PROFIBUS

station address of the CBOX;

4. The third bytes of both the input and output areas are equal to SAP (either 0 or

2 in these examples).

5. The fourth byte of the input area is equal to the effective barcode string length

inserted in the input area itself.

6. The barcode string is inserted starting from the fifth byte of the input area.

7. All the other bytes of the output area are not relevant.

6.3 Example of exchanges

In the example case we set:

• INPUT AREA LENGTH = 16 ;

• OUTPUT AREA LENGTH = 8;

• PROFIBUS C-BOX station address = 3

Start of DPD exchanges with SAP=0

Input Area

0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00

Output Area

0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00

Data sent from C-BOX to host

......

// C-BOX receives a barcode string equal to "0123456" from the scanner

// and sends it to Master.

Input Area

0x01 0x03 0x00 0x07 0x30 0x31 0x32 0x33 0x34 0x35 0x36 0x00 0x00 0x00 0x00 0x00

Output Area

0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00

Before any relative update, the input and output areas are generally full

of 0