
Manual – IPOSplus®
83
6
Modulo function
Position Detection and Positioning
Step 3: Modulo range of representation and maximum target position
Check the modulo range of representation:
The product of the modulo encoder resolution and modulo numerator must be < 2
31
(decimal 2 147 483 648).
Modulo numerator x modulo encoder resolution = 1021977 × 4096 = 4 186 017 792
The condition has not been met, the required target position cannot be represented. This
application would result in positioning errors. The system sets the +/- bit when a value
is specified, for example, a target position of 180°; the drive is positioned incorrectly.
Solution: Select a gear unit with a different ratio.
The target position that can be represented can be increased by selecting another gear
unit with different division factors for the number of teeth (i.e. parts of the numbers of
teeth would cancel one another out in the calculation).
6.7.6
Frequently asked questions
• Is there a complete program to use with the modulo function?
• Yes, the "Modulo Positioning" application module with optional control via fieldbus
or hardware terminal.
• Why is it recommended to set P960 to SHORT?
• The travel strategy is adhered to strictly when the target position is set during
standstill. If the drive is set to P960 = CW, for example, when the target position
is set, only one increment CW away, the drive moves through a complete rotation.
• Why does positioning not start once the target position has been sent?
• The drive must be started in the "... & IPOS" operating mode.
• A travel strategy must be selected via SHELL P960.
• Before setting the H454 ModTagPos IPOS
plus®
variable, the drive inverter must
be in the status A "Technology option".
• Can the target position be written cyclically?
• For targets in the range 0° to 359,999° or 0 increments ... 65535 increments: Yes.
• If target positions
≥
360° are written cyclically, this causes "Endless positioning".
• Can incremental positioning be performed if the modulo function is activated?
• Yes, but to avoid unwanted "Cross effects", modulo positioning should be
switched off in the SHELL parameter 960.
• After the reference travel, only the IPOS
plus®
variable H455 MOD.ACTPOS is set
to 0, NOT the incremental actual position ACTPOS.MOT in variable H511.
• What causes the error IPOS-ILOOP F10?
• The interpreter of the IPOS program detects a command with invalid operands.
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