Siemens SIMATIC PN/BACnet LINK - Page 40

Functions
4.5 Acyclic data exchange
PN/BACnet LINK
40 Operating Instructions, 10/2017, A5E39895543-AA
WriteProperty
For a "WriteProperty", in addition to the parameters required for "ReadProperty", the data
record must also contain the property value and the priority of the write job.
Table 4- 7 WRREC (Write data record) - RecordWrite data record structure for WriteProperty
service
Element
Type
Meaning
PNreq
UINT8
PROFINET service: Property access = 1
BNreq
UINT8
BACnet service: "WriteProperty" = 0x0F = 15
DNET
UINT32
Network number
Device ID UINT32 BACnet device instance number
ObjectID
UINT32
BACnet ObjectID (type and instance)
PropertyID
UINT32
PropertyID
ArrayIndex
INT32
Property index (-1 = no index)
Priority
UINT16
BACnet priority (1 ... 16)
Data type
UINT16
BACnet data type of the property (according to BACnet specification)
Len
UINT16
Length of value in bytes
Value
Array
BACnet property value in ASN.1 format
The result is located in a data record, which must then be read.
Table 4- 8 RDREC (Read data record) - data record structure for WriteProperty result
Element
Type
Meaning
PNresp
UINT8
PROFINET error number (0 == no error)
BNresp
UINT8
BACnet error number (0 == no error)
DNET/ErrorClass
UINT32
Network number (BNresp == 0)/BACnet error class (BNresp != 0)
Device/ErrorCode UINT32 BACnet device instance (BNresp == 0)/BACnet error code
(BNresp != 0)
ObjectID
UINT32
BACnet ObjectID (type and instance)
PropertyID
UINT32
PropertyID
ArrayIndex
INT32
Property index (-1 = no index)