Pseudo closed loop

The function module operates in "pseudo" closed-loop mode.
The encoder signal is always evaluated at the end of a travel profile and a position correction is triggered via the profile generator.
The encoder signal is taken into account by the controller.
The setpoint for the current controller is generated by the higher-level profile generator.
The actual position corresponds to the encoder value, normalized to position.
An encoder value is output.

Structure

Start	Start parameter
Limit Position	Position limiting
Limit Voltage	Voltage limiting
Position control	Position controller
Current control	Current controller
M	Motor
Limit Velocity	Speed limitation
Limit Current	Current limitation
PtP	PtP position profile
int. PS	Internal power stage
Encoder	Actual encoder value

Operating principle

In pseudo closed loop mode, the setpoint for the current controller is generated by the higher-level profile generator. The position and speed control loops are not closed and therefore the encoder signal is not evaluated in the control loops. In contrast to open loop, with pseudo closed loop the encoder signal is evaluated after the end of a profile operation and, if necessary, a position correction is triggered via the profile generator. The following objects are used with pseudo closed loop:

Pseudo closed loop
0x8F00-01 – Encoder feedback configuration	5: "Pseudo closed loop" setting
0x8100-02 – Status word 0x8480-09 – Target window	In the status word, "Target position reached" bit 10 is set if the deviation from the target position is smaller than the parameterized target window.
0x8480-10 – Lag error	You can use this object to query the deviation between the setpoint and actual value.
0x8480-11 – Lag error limit warning 0x8100-05 – Bit bar – Warnings	You can use this object to specify a limit above which a warning will be issued via bit 8.
0x8480-12 – Lag error limit error 0x8100-03 – Error code	You can use this object to specify a limit above which an error will be output via bit 8. In addition, the module switches to the error state with positioning error 0x8611 in the event of an error.
0x8100-02 – Status word	Bit 12 in the status word remains set during the position correction.
0x8480-17 – Pseudo Closed Loop: Number of correction cycles	You can use this object to define the number of correction cycles.

[P]	Actual position
[T]	Setpoint position
[t]	Time axis
[1]	The first profile operation is started. The drive is enabled.
[2]	Profile operation continues to run while the drive is blocked.
[3]	Profile operation continues to run. The drive is unblocked.
[4]	Profile operation is complete. Due to the high control deviation, the second profile operation is started.
[5]	The actual position is equal to the setpoint position and the profile operation is ended.