BECKHOFF BK3xx0 - Manual (Page 55)

Notes on the Documentation
Fieldbus Components 53
DPV1 - Acyclic Data Transfer
DPV1 Interface
By default, one MSAC_C1 connection and one MSAC_C2 connection with 52 bytes of data (4 bytes DPV1 header
plus 48 bytes of user data) are supported. The MSAC_C1 connection is established along with cyclic connection, and
can be activated via the UserPrmData:
Byte Bit Value: Description
0 7 1: MSAC_C1 connection is activated
The MSAC_C2 connection can be used either by the C1 master (which communicates with the slave cyclically) or by
a C2 master (which then only communicates with the slave acyclically), and has its own establishment of connection.
The parameters at the establishment of the MSAC_C2 connection (Feature_Supported, Profile_Feature_Supported,
Profile_Ident_Number, etc.) are not examined, and the parameters of the request are mirrored in the response.
Slot_Number = 0 addresses PROFIBUS coupler data, Slot_Number > 0 addresses the data of the function
module(s).
PROFIBUS coupler data (Slot_Number = 0)
The data associated with the PROFIBUS coupler is addressed via an index:
Index Access Description
1-2 R/W Module assignment in multi-configuration mode
5 R Firmware information
9-19 R/W Device configuration (Table 9)
90 R K-Bus status (Table 90)
98 R/W Internal cycle time
99 W Commands: local bus reset, starting or stopping the internal cycle time measurement
Function module data (Slot_Number > 0)
Depending on the type of function module, access is made either to the registers (max. 4 channels, each with 64
registers) or to the parameters (only supported by a few function modules, where the quantity of data is insufficient
for the register model)
Accessing registers
Index Access Length Description
0-63 R(/W) 2 Registers 0-63 of the channel 1 in the function module
64-127 R(/W) 2 Registers 0-63 of the channel 2 in the function module
128-191 R(/W) 2 Registers 0-63 of the channel 3 in the function module
192-254 R(/W) 2 Registers 0-63 of the channel 4 in the function module
Accessing parameters
Index Access Length Description
0 R(/W) 4-32 (must be divisible by 4) Parameters 0x0000-0x0007 of the function module
1 R(/W) 4-32 (must be divisible by 4) Parameters 0x0008-0x000F of the function module
... ... ...
127 R(/W) 4-32 (must be divisible by 4) Parameters 0x03F8-0x03FF of the function module