Referencing - Siemens LMV37.4 Series Basic Documentation

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11.3 Referencing

An incremental transducer is used for position feedback. This means that referencing of
the actuators must be performed after power-ON. In addition, at the end of each
shutdown in phase 10, the actuators are referenced to ensure that individual stepping
errors, which could lead to shutdown, do not accumulate. If a position error occurs, the
system switches to the safety phase (phase 01), enabling the actuators with detected
position errors to be referenced. During the following phase 10, the only actuators
referenced are those that were not referenced before in the safety phase (phase 01).
The position of the reference point can be selected depending on the type of burner,
either the Closed position (<0°) or the Open position (>90°).
When using actuators SQM33.6 or SQM33.7, the actuator type (parameter 613) must
be set (refer to chapter Actuator type / running time).
Note!
If a SQM33.7 is used, the modulating operating ramp (parameter 544) may need to be
increased (refer to chapter Running speed / maximum curve slope).
No. Parameter
Selection of reference point
Index 0 = fuel
601 Index 1 = air
0 = close (<0°)
1 = open (>90°)
Direction of rotation of actuator
Index 0 = fuel
602 Index 1 = air
0 = counterclockwise
1 = clockwise (exclusively for SQM3...)
603 Tolerance limit of position monitoring (0.1°)
Index 0 = fuel
Index 1 = air
Greatest position error where an error is securely detected
→ Error detection band: (parameter 606 – 0.6°) up to parameter 606
611 Type of referencing
Index 0 = fuel
Index 1 = air
0 = standard
1 = stop within the usable range
2 = internal stop
3 = both
613 Type of actuator
Index 0 = fuel
Index 1 = air
0 = 5 s / 90° (SQN13... / SQN14..., SQM33.4, SQM33.5)
1 = 10 s / 90° (SQM33.6)
2 = 17 s / 90° (SQM33.7)
Application note!
Single-sided load torque is recommended due to the type of gear train for the
SQM33.6 / SQM33.7 actuators. In the event of load on both sides, a backlash of 0.3°
must also be considered in addition to plant design or setting
Basic documentation LMV37.4...
11 Actuators X53 / X54
CC1P7546en
20.09.2013