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Entry type: FAQ Entry ID: 108965481, Entry date: 01/27/2015

SINAMICS G120 (CU2x0x-2): Changing Setpoint between AI0 and AI1 using free function blocks

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Summary In MM4 inverters, we need Comand Data Set (CDS) switch-over to select different setpoint sources. In SINAMICS G120 (CU2x0x-2) inverters, we can use free function block NSW (numeric change-over switch) to do this. ...

How can you change the Setpoint between AI0 and AI1 by using free function blocks in SINAMICS G120

The free function block NSW (numeric change-over switch) can be used to implement the function.

Change over speed setpoint between AI0 and AI1 by DI3 by Using FFBs in CU240B/E-2.

Parameters setting and description

Parameters setting Description
P20221=5 Assign NSW0 to runtime group 5 (time slice of 128 ms)
P20222=610 Run sequence of the time block within runtime group 5
P20218[0]=755.0 Connect the AI0 to the 1st input of NSW0. r755.0 = AI0 actual value in percent
P20218[1]=755.1 Connect the AI1 to the 2nd input of NSW0. r755.1 = AI1 actual value in percent
P20219=722.3 Connect DI3 to the signal source of switch setting of NSW0. r722.3 = the status of DI3
P1070[0]=20220 Connect the output of NSW0 to the signal source of speed setpoint

According to the parameter setting, AI0 is selected when DI3 is in low level. And AI1 is selected when DI3 is in high level.

NSW0 is computed every 128 ms as it is assigned to runtime group 5. The maximum delay time is 128 ms from action of DI3 to change-over completion.

Further information
SINAMICS G120 and G120P: Where do I find an instruction describes the functionality of the free function blocks? Entry-ID: 85168215

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