Profichip VPC3+S - Page 67

PROFIBUS DP Extensions 7
VPC3+S User Manual
Revision 1.04
67
Copyright © profichip GmbH, 2012
Byte
Bit Position
Designation
7
6
5
4
3
2
1
0
0
0
0
Block_Length
Header_Byte
1
1
0
0
0
0
0
1
1
Status_Type
2
0
0
0
0
0
0
0
0
Slot_Number
3
0
0
0
0
0
0
0
0
Status_Specifier
4
Publisher_Addr
5
Link_
Status
Link_
Error
0
0
0
0
0
Data_
Exist
Link_Status
6
:
61
further link entries
Link_Status:
bit 7
Link_Status :
1 = active, valid data receipt during last monitoring period
0 = not active, no valid data receipt during last monitoring period (DEFAULT)
bit 6
Link_Error:
0 = no faulty Broadcast data receipt (DEFAULT)
1 = wrong length, error occurred during reception
bit 0
Data_Exist:
0 = no correct Broadcast data receipt during current monitoring period
(DEFAULT)
1 = error free reception of Broadcast data during current monitoring period
Figure 7-10: DXB_Link_Status_Buf (specific link is grey scaled)
Processing Sequence
The VPC3+S processes DXBout-Buffers like the Dout-Buffers. The only
difference is that the DXBout-Buffers are not cleared by the VPC3+S.
The VPC3+S writes the received and filtered broadcast data in the 'D'
buffer. The buffer contains also the Publisher_Address and the
Sample_Length. After error-free receipt, the VPC3+S shifts the newly filled
buffer from 'D' to 'N'. In addition, the DXBout interrupt is generated. The
user now fetches the current output data from 'N'. The buffer changes from
'N' to 'U' with the Next_DXBout_Buffer_Cmd.