Siemens SINAMICS G120 CU230P-2 HVAC Operating Instructions Manual page 279

Scaling examples
● Speed:
● Temperature:
Example: Logic combination of two digital inputs
You want to switch on the motor via digital input 0 and also via digital input 1:
1. Activate a free OR block by assigning it to a runtime group, and define the run sequence.
2. Interconnect the status signals of the two digital inputs DI 0 and DI 1 via BICO to the two
3. Finally, interconnect the OR block output with the internal ON command (P0840).
Table 7- 51
Parameter
P20048 = 1
P20049 = 60
P20046 [0] = 722.0
P20046 [1] = 722.1
P0840 = 20047
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
Reference speed p2000 = 3000 rpm, actual speed 2100 rpm. As a consequence, the
following applies to the scaled input quantity: 2,100 / 3,000 = 0.7.
Reference quantity is 100 °C. For an actual temperature of 120 °C, the input value is
obtained from 120 °C / 100 °C = 1.2.
Note
Limits within the function blocks should be entered as scaled values. The scaled value
can be calculated as follows using the reference parameter: Scaled limit value = physical
limit value / value of the reference parameter.
The assignment to reference parameters is provided in the parameter list in the individual
parameter descriptions.
inputs of the OR block.
Parameters for using the free function blocks
Description
Assignment of block OR 0 to runtime group 1 (factory setting: 9999)
The block OR 0 is calculated in the time slice with 8 ms
Definition of run sequence within runtime group 1 (factory setting: 60)
Within one runtime group, the block with the smallest value is calculated first.
Interconnection of first OR 0 input (factory setting: 0)
The first OR 0 input is linked to digital input 0 (r0722.0)
Interconnection of second OR 0 input (factory setting: 0)
The second OR 0 input is linked to digital input 1 (r0722.1)
Interconnection of OR 0 output (factory setting: 0)
The OR 0 output (r20047) is connected with the motor's ON command
7.9 Application-specific functions
Functions
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