Instruction manual

Connection box C-BOX 300

The C-BOX PROFIBUS protocol implementation

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

SAP=2) will permit application events to be queued in the opposite direction, waiting

for use by the C-BOX application layer.

The queues are sized in the following way:

• X elements of 32 bytes each for input queue (flow from C-BOX to the Master sta-

tion);

• Y elements of 32 bytes each for output queue (flow from the Master station to C-

BOX).

The number of 32-byte elements X and Y are application dependent. Contact your

Pepperl+Fuchs distributor for further information.

The queues may be flushed by the Master station through the SAP=255 primitive.

This is generally done at the Master startup if the Master station wants to cancel all

the previous buffers that were generated before its startup. However, the Master

station is free to decide not to cancel them.

5.11 Application data area with SAP = 0

SAP = 0 is at the moment used only to transfer barcode events from C-BOX 300

towards the Master station.

In IN[4] we can find the first significant byte of the application buffer (the same first

byte we would have seen if C-BOX 300 had transmitted the barcode buffer onto a

normal serial line instead of the PROFIBUS line).

Obviously the structure of the application buffer and its length strictly depends on the

selected format on the C-BOX 300. If the length of the application buffer is larger than

MaxInBytes-4 the application buffer is split into more pieces through an automatic

fragmentation process.

5.12 Services available with SAP = 255

This value of SAP is used for management of the link from the master to the slaves.

At the moment only one DPD management service may be issued: the flush of the

internal queues.

This may be issued anytime.

FLUSH QUEUE Service Description:

REQUEST: Flush data buffers (issued by the Master station to C-BOX)

ACTION: Flush all information from previous decoding phases

RESPONSE: Command accepted, Command rejected

(generated by C-BOX as response to a previous request from the

Master station).