Siemens SINAMICS V20 - Page 16

3 Principle of Operation
3.2 Blocks
SINAMICS V20 at S7-1200/1500 via USS
Entry ID: 109480894, V1.0, 09/2018
16
 Siemens AG 2018 All rights reserved
Table 3-2: Block parameters of the UssCyclic FB
Name
Data type
Meaning
IN parameter
STW
Word
Control word of the SINAMICS
V20
With the UssCyclic FB, the
following STW bits can be
transferred to the SINAMICS
V20:
ON/OFF1 (bit 00)
OFF2 (bit 01)
OFF3 (bit 02)
Fault ack. (bit 07)
Reverse (bit 11)
speedSetpoint
Real
Speed setpoint
Specified as a percentage of the
frequency of the inverter output
and therefore independent of the
pole pair number and motor slip.
OUT parameter
ZSW
Word
Status word of the SINAMICS
V20
With the UssCyclic FB, the
following ZSW bits can be
received from the SINAMICS
V20:
Inverter running (bit 02)
Motor runs right (bit 14)
ON inhibit active (bit 06)
Inverter fault active (bit 03)
actual Speed
Real
Actual speed
Specified as a percentage of the
frequency of the inverter output
and therefore independent of the
pole pair number and motor slip.
Function
In this application example, the block only has the task to ensure the supply of the
called USS_DRV or USS_Drive_Control system instruction.
The following default settings were made in the associated InstUssCyclic instance
DB:
 STW = 0806
hex
This means that bits 01 (OFF2), 02 (OFF3) and 11 (Reverse) have already
been set when the controller is restarted.
 speedSetpoint = 50.0
Ensures that the drive immediately ramps up with the parameterized ramp-up
time to 50% of its rated speed when the ON/OFF1 button is pressed.