5.5.1 Basic function
In the Cyclic Synchronous Position operating mode, the Motion Controller controls the posi-tion of the drive. The set-point is specified via object 0x607A by the master or via a local sequence program. Scaling of the set-points and actual values via the factor group is always taken into account.
Unlike Profile Position mode, the speed profile is calculated in the master and not in the drive (slave). Settings for the speed profile are not taken into account by the Motion Con-troller.
Cyclic Synchronous Position mode is especially well suited for combination with industrial master controls that generate interpolated movements for multiple axes. Here, the master specifies the target position in short, cyclical intervals. The drive then performs the torque control, speed control and position control.
Fig. 52: Cyclical updates of the set-point
Optionally, the master can provide additional values to the speed and torque feedforward control.
Pos
t Updates of the target position
Fig. 53: Overview of Cyclic Synchronous Position mode The position set-point can be specified in two different ways:
Absolute set-point:
In Cyclic Synchronous Position mode, set-points are interpreted as absolute value. The next position to be reached is specified as the target. The set-point should be generated incrementally.
Cyclical set-point:
For rotary tables, the position range can be limited to one revolution of the application via the position ranges. With the Position Option Code in object 0x60F2, you can then set that the next position is to be reached via the shortest distance.
Starting a movement task
Each newly received target position is immediately passed to the controller as set-point.
No explicit start of the movement takes place.
If the master has also calculated pre-control values for the speed and the torque in addition to the position set-point, these can be applied in addition via offsets 0x60B1 and 0x60B2. The following error can thereby be reduced.
The controller provides the possibility of interpolating between two consecutive set-point values of a cyclic interval. This smooths the movement significantly. To activate this option, check the refresh rate of the master and set object 0x2332 accordingly in multiples of 100 μs.
Pos*
Velocity Offset Act Pos
Act n
Effective sub-functions
Control of the position via the controller according to chap. 4.3, p. 25
Measurement of the actual values
Monitoring of the movement for slippage and following error
Optional: Torque and motor speed limitation
Estimate of the motor temperature and output stage temperature as a protective func-tion
Monitoring of the movement range via the Software Position Limits and limit switches
5.5.2 Statusword/controlword Cyclic Synchronous Position mode
In Cyclic Synchronous Position operating mode the controlword is not assigned to any oper-ating mode-specific bits. Operoper-ating mode-specific bits are assigned to the statusword.
Tab. 57: Operating mode-specific bits of the statusword (Cyclic Synchronous Position mode)
Bit Function Description
10 Reserved 0: Reserved
12 The drive follows the command value
0: The drive does not follow the command value; the target position is ignored 1: The drive follows the operating value, the target position is used as an input to
the position control
13 FollowingError 0: The actual position follows the instructions without a following error 1: Permissible range for the following error exceeded
5.5.3 Control structure in Cyclic Synchronous Position mode
Fig. 54: Motion Manager view of the Cyclic Synchronous Position mode
5.5.4 Example
For a servo drive, the target position is specified by the master.
Controller parameters are set acc. to chap. 4.3, p. 25
Parameters for the following error (Following Error Window) are adapted to the appli-cation
Operating mode is selected via 0x6060.00 = 8
Control is activated (the drive is in the Operation Enabled state)
Write set-point in 0x607A.00.
The drive begins the movement task immediately. If the set following error is exceeded, this is indicated in bit 13 in the statusword.
Object= adjustable Object = not adjustable
n*
pos Mode
(0x6060)
Range Limits (0x607B)
SW Limits (0x607D)
Position Control (0x2348.01)
Velocity Control
Actual Value 0x606C
Velocity Feed Forward (0x2350.01) Discrete Source
(0x2331.04)
Target Position (0x607A.00)
P pos*
APC
CSP PP
Not in APC Mode
5.5.5 Options for operation with cyclical position
Linear movement between two end positions
Cyclical rotating movement on a rotary table
Options
In the Position Option Code (0x60F2), the behavior of the drive during cyclical rotary move-ments can be configured.
The positions (set-point and actual value) always range between a lower and an upper maximum value. The maximum values can be permanently set via the Software Position Lim-its (0x607D).
By specifying the next set-point, the move-ment direction is clearly specified
Via the position range limits, the range of the actual position can be limited such that it always corresponds to the absolute position within a revolution, e.g., 0°…360°. The current position within the set range is thereby always indicated, e.g., even after multiple
revolutions.
With standard settings, the direction of move-ment is ascertained from the sign of the fol-lowing error here as well. Movement is then, e.g., from 350° to 10°, a distance of –340°.
If the motor is coupled to the rotary table via a gearhead, the conversion of rotary table position to motor position can be performed automatically via the gear ratio of the factor group. The set-points and actual values as well as the range limits are then specified in the positions at the output of the gearhead.
Standard option:
The direction of movement is determined independent of the position range limits from the sign of the control deviation.
Shortest option:
After specifying a new set-point, the shortest path to the target is travelled, taking into account the position range limits. It is thereby possible to travel beyond the ranges.
Motor Nut
Pos = 0 Pos = Max
Reference Switch
360° = 3600 0°
0x60F2.00 = 00 00
0x60F2.00 = 00 C0
Example
Controller parameters are set acc. to chap. 4.3, p. 25
Parameters for following error monitoring (Following Error Window) are adapted to the application
Operating mode is selected via 0x6060.00 = 8
Control is activated (the drive is in the Operation Enabled state) 1. Set Position Option Code in object 0x60F2.00 = 00C0.
2. Adjusting the movement range:
0x607B.01 = 0
0x607B.02 = 3599
3. Write set-point in the range 0…3599 in object 0x607A.00.
The drive begins the movement task immediately. If the set following error is exceeded, this is displayed in bit 13 of the statusword.