Beckhoff EL6731 Documentation page 47

MSAC-C1 Write
ADS-Write parameters
Net-ID
Port
IndexGroup
IndexOffset
Length
Data
C2 Connection (MSAC-C2)
The C2 connection is as a rule intended for a second master (C2 master) that does not communicate with
the slave cyclically, but it is also possible for the C1 master to make use of the C2 connection. In order for a
slave to be able to use the C2 connection, the slave must support DPV1 (this means that the line
"DPV1_Slave = 1" and the key word "C2_Max_Data_Len" with an appropriate length must be in the GSD
file).
The connection is automatically established by the master as soon as a Read, Write or Data_Transport
access is requested; it can, however, also be explicitly established through an Initiate. When the connection
is being established automatically, the master sends the Initiate parameters that have most recently been
passed (see the description of Initiate), and initializes the Initiate parameters with 0 after a TwinCAT start (or
restart); monitoring of the connection is an exception - this is initialized in accordance with the value set in
the System Manager (Watchdog under DPV1 Class 2 on the slave's Profibus [} 96] tab).
It is also necessary for the C2 functionality to be activated for each slave that is to be addressed using C2
services by selecting the Enable check box under DPV1 Class 2 (see the slave's Profibus [} 96] tab).
If a different master performs cyclic data exchange with the slave, then the "No cyclic connection" setting
must be chosen under DP Class 2 (see the slave's Profibus [} 96] tab). This could, for instance, be useful
in order to be able to debug a BC3100/IL23xx-C310 over PROFIBUS, even though it is being operated by an
external controller.
MSAC-C2-Read is represented in ADS-Read, MSAC-C2-Write in ADS-Write, MSAC-C2-Data_Transport in
ADS-ReadWrite, MSAC-C2-Initiate in ADS-ReadWrite, and MSAC-C2-Abort in ADS-Write:
MSAC-C2 Read
ADS-Read parameters
Net-ID
Port
IndexGroup
IndexOffset
Length
Data
MSAC-C2 Write
ADS-Write parameters
Net-ID
Port
IndexGroup
IndexOffset
Length
Data
EL6731
Meaning
Net-ID of the master (see the device's ADS [} 92] tab)
0x1000 + station address of the slave
Slot number (DPV1 parameter)
Index (DPV1 parameter)
Length of the data that is to be written
In request: data that is to be written
Meaning
Net-ID of the master (see the device's ADS [} 92] tab)
0x1000 + station address of the slave
0x100 + slot number (DPV1 parameter)
Index (DPV1 parameter)
Length of the data that is to be read
In response: data that has been read
Meaning
Net-ID of the master (see the device's ADS [} 92] tab)
0x1000 + station address of the slave
0x100 + slot number (DPV1 parameter)
Index (DPV1 parameter)
Length of the data that is to be written
In request: data that is to be written
Version: 2.8
Parameterization and commissioning
47