Free Function Blocks; General Remarks - Siemens SINAMICS Series Operating Instructions Manual

10.36

Free function blocks

A logic operation, which connects several states (e.g. access control, plant status) to a
control signal (e.g. ON command), is required for controlling the drive system in a wide
variety of applications.
Along with logic operations, a number of arithmetical operations and storing elements are
becoming increasingly important in drive systems. This functionality is available as a
"Free function blocks" function module (FBLOCKS) on the drive object type of the
SINAMICS DCM.

General remarks

● Exact information on the scope of the blocks, about parameter assignment and about
commissioning the free function blocks is available in the "SINAMICS" Free function
blocks" manual. This chapter describes the special features of the free function blocks
with SINAMICS DCM.
● This additional functionality increases the CPU time load. That means the maximum
possible configuration with a Control Unit may be restricted.
● The free function blocks are restricted in their scope to 52 blocks per drive object (DO).
Furthermore, the unassigned function blocks as compared to DCC cause significantly
higher CPU time load. If that does not suffice, the application can be implemented with
the DCC technology option. See Chapter "Drive Control Chart (DCC) (Page 663)".
● In the SINAMICS DCM, simultaneous use of the free function blocks and the DCC
technology option are feasible.
● With the SINAMICS DCM, parameters that specify scaled variables have the unit
"Percent". With free function blocks, parameters that specify scaled variables have no
dimension. When setting parameter values, the unit of the parameter must always be
taken into account. The unit is specified in the List Manual and is displayed in STARTER
and on the AOP30.
Remark:
The relationship between percent variables and dimensionless variables is 100%
corresponds to 1.00.
The conversion is performed according to the formula: Y=X/100%.
Example: The fixed value r52401 is used as the input value of the limit monitor
(p20266 = 52401). p50401 and r52401 both have the unit "%". If the value "50%" is
specified at p50401, the value "50%" appears at r52401. The value "50%" (= 0.5) is
therefore effective as the input signal X of the limit monitor. If a mean interval value of
50% is to be set, then p20267 = 0.5 must be set because parameter p20267 is
dimensionless and the relationship 50% = 0.5 applies.
SINAMICS DCM DC Converter
Operating Instructions, 12/2018, A5E34763375A
X..percent variable
Y..dimensionless variable
Descriptions of functions
10.36 Free function blocks
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