Burkert Type 8644 - Manual (Page 51)

8644/phoenix - 47
S
YSTEM
D
ESCRIPTION
The communication protocol for the parameter data in local bus is referred to in the following as PCP.
The objects on the DPV1 field bus node:
One of the simpelst solutions for exchanging data is DPV1 in the C1 master. The connection establishment
(Initiate) is omitted, since there is already a connection between master and slave in the cyclical data
traffic. Data exchange can be commenced directly.
With C2 communication, the data fields are identical to those of C1 communication. The SAPs (Service
Access Points) are 51 for C1 communication, for C2 communication 48 and 50 (49 for the connection
establishment). Connection establishment (Initiate) or connection termination (Abort) via SAP 49 and 50
between master and slave should be regarded as an additional effort. Use DPV1 devices so that the
routines for connection administration are easy to realize.
Only one active DPV1 is ever permitted. Overall you have the opportunity to connect up to eight PCP
capable terminals / modules to the DPV1 field bus node.
The process
Note that the PCP data of the I/O modules are mainly addressed via 16 bit long object indices.
Unfortunately DPV1 only provides fields for 8 bit long indices. Therefore, drawing on the PROFIDrive profile
a sequence of 2 (4) steps has arisen:
Read (Write/Polling - Read/Polling)
1. a) Dispatching the request as write (read) to slot x.
b) Polling the answer onto the write (read)
2. a) Dispatching a read to slot x
b) Polling the answer onto the read
Write (Write/Polling - Read/Polling)
1. a) Dispatching the request as write (write) to slot x.
b) Polling the answer onto the write
2. a) Dispatching a read to slot x
b) Polling the answer onto the read
DPV1 in the C1 and C2 master
The intention of these objects is to show how access to an intelligent slave can be obtained via voarious
masters.
NOTE Not all controls / configuration tools support DPV1, or only support it with limitations.
Check this context before programming the application. If DPV1 is not sufficiently
supported, you have the opportunity to use the functions via the cyclical process data
channel.
Slot Index Service Comment
1 ... 63 2 Write Module parameter
0 3 Write Control byte (diagnosis format, manual peripheral error
acknowledgement ... )
0 4 Write Acknowledgement (local bus event)
1: Local bus stop acknowledgement
2: Peripheral fields acknowledgement
0 5 Read Overview of PCP modules and status
1 ... 63 47 Read/Write PCP data to profile profidrive
1 ... 63 48 Read/Write PCP data