DIRDRIVE (loop control disabled) mode is used to free the axis from slave mode. The axis acts as a digital/analog converter (D/A converter) and the position loop is inoperative.

Axis behavior can be analyzed independently of the process control loop.

Loop control disabled mode is selected by assigning the value of 1 to the MOD_SEL (%QWr.m.c.0) word.

When a change of mode is requested, the moving part first stops then the mode is actually changed. When the command to change to loop control disabled mode is taken into account, the IN_DIRDR (%Ir.m.c.21) bit is set to 1.

The loop control disabled mode features the movement command DIRDRV (%Qr.m.c.0).

The drive is controlled at a voltage of between -UMAX and +UMAX (the value UMAX is defined in the configuration screen). It is expressed in mV. Application of this setpoint is rounded off into multiples of 1.25 mV (For example, if 1004 mV is requested, the setpoint will be rounded down to 1003.75 mV, and the display screen will show 1003 mV).

The voltage setpoint is periodically sent by the variable PARAM (%QDr.m.c.2). The variable sign gives the direction of movement. The software fault checks are inhibited (excepted for soft stop checks if the axis is referenced).

In order to take in account the mechanics during a setpoint change, the acceleration/deceleration value is respected when switching to a new value.

The general execution conditions for a DIRDRIVE function are as follows:

A movement stop can be caused by: