Control Of Drives Through Drivebus; Db Elements; Pc Elements - ABB Advant Controller 80 User Manual

Control of Drives
through DriveBus

DB Elements

PC Elements

4-12
DriveBus has a fibre optic DDCS-protocol interface. A maximum of
twelve drives (or other NAMC-based units) can be connected to
DriveBus by using NDBU-85 or NDBU-95 branching units.
The DRB0L1 database element activates the drive node(s) and defines
an area called the drive buffer for each. The drive buffer contains the
records that are used for transmitting and receiving buffers for cyclic
messages.
The DRB0L1 element must be defined in the application prior to the PC
elements.
Figure 4-7 The DRB00 DB element.
The ACSRX (DRive TRAnsmit and DRive RECeive) element is used for
sending and receiving data sets. Data sets consist of three 16-bit
words, called data words. The number of data sets supported by the
drive is explained in the drive manuals, as is the coding and scaling of
the individual data words.
The ACSRX element uses only the cyclic message types supported by
the DDCS protocol used by DriveBus. The source for the received data
is selected via an element input parameter, specifying the drive number
and signal index (dataset number). Consult the drive manuals.
During normal operation, possible ACSRX overload is detected.
Note: Ensure that the program block containing the ACSRX element is
executed frequently enough not to cause a communication timeout
error.
AC 80 User's Manual