Siemens SINAMICS DCM Operating Instructions Manual page 35

● Free function blocks (FBLOCKS)
● Drive Control Chart (DCC)
SINAMICS DCM DC Converter
Operating Instructions, 1.2012, C98130-A7066-A1-05-7619
In a wide variety of applications, a logic operation connecting several states (e.g. access
control, system status) to a control signal (e.g. ON command) is required to control the
drive system. In addition to logic operations, however, drive systems require
mathematical operations and latching elements.
These functions are available in the form of the "free function blocks" function module.
There is a range of elementary function blocks that are freely available for use:
– Logic function blocks (AND, OR, XOR, inverter)
– Calculation function blocks (adder, multiplier, divider, absolute-value generator)
– Time function blocks (pulse generator, pulse contracting block, ON delay, OFF delay,
pulse stretching)
– Memory function blocks (RS flip-flop, D flip-flop)
– Switch function blocks (binary selector switch, numerical selector switch)
– Control function blocks (limiter, smoothing element, integrator, differentiator)
– Complex function blocks (double-sided limit monitor with hysteresis)
DCC is available for applications requiring a more complex method of controlling the drive
system, which cannot be accomplished using the free function blocks. DCC makes it
possible for one of the interconnected elementary function blocks to generate a graphical
depiction of an existing function diagram and load it to the SINAMICS DC MASTER. The
function diagram may contain up to 750 function blocks. It is possible to configure the
time slices in which the individual parts of the function diagram are processed.
Note:
A DCC function diagram can be loaded not only onto the CUD in the left-hand slot, but
also to an optional second CUD in the right-hand slot.
The closed-loop drive control is computed on the CUD in the left-hand slot. which means
that it only provides a small amount of computing capacity for a DCC function diagram (in
other words, either only a few function blocks can be computed, or computing can only be
carried out in a long time slice).
The CUD in the right-hand slot is primarily available (in addition to the operating system)
for one DCC function diagram only.
Description
33