External - TML Programming Details

External – TML Programming Details

In the external modes, you program the drives/motors to work with an external reference provided by another device. There are 3 types of external references:

•	Analogue – read by the drive/motor via a dedicated analogue input (10-bit resolution)

•	Digital – computed by the drive/motor from:

•	Pulse & direction signals

•	Quadrature signals like A, B signals of an incremental encoder

•	Online – received online via a communication channel from a host and saved in a dedicated TML variable

When the reference is analogue or online, you can set a:

•	Position external mode, where the motor is controlled in position and the external reference is interpreted as a position reference

•	Speed external mode, where the motor is controlled in speed and the external reference is interpreted as a speed reference

•	Torque external mode, where the motor is controlled in torque and the external reference is interpreted as a current reference.

•	Voltage external mode, where the motor is controlled in voltage and the external reference is interpreted as a voltage reference.

When the external reference is digital, the option for the input signals: pulse & direction or quadrature encoder is established during the drive/motor setup. The drive/motor performs only position control having as goal to follow the position reference computed from the input signals with a preset gear ratio. In this case, the drive/motor actually works in electronic gearing mode, where you can find further details.

In position external mode with analogue or online reference, you can limit the maximum speed at sudden changes of the position reference and thus to reduce the mechanical shocks. This feature is activated by setting UPGRADE.2=1 and the maximum speed value in CSPD.

In speed external mode with analogue or online reference, you can limit the maximum acceleration at sudden changes of the speed reference and thus to get a smoother transition. This feature is activated by setting UPGRADE.2=1 and the maximum acceleration value in CACC.

In torque or voltage external mode with analogue reference, you can choose how often to read the analogue input: at each slow loop sampling period or at each fast loop sampling period.

When using the analogue reference, during the setup phase, you specify the reference values corresponding to the upper and lower limits of the analogue input. Depending on the control mode selected, these values may be position or speed or torque or voltage references. You may also select a dead-band symmetrical interval and it’s center point inside the analogue input range. While the analogue signal is inside the dead-band interval, the output reference is kept constant and equal with value corresponding to the dead-band center point. This option is especially useful when you need to set a precise reference, which doesn’t change in the presence of some noise on the analogue input signal. If dead-band width is set to zero, the dead-band is disabled.

Remark: Setup tools like EasySetUp, automatically compute the value of the TML parameters needed to convert the analogue input range into the desired reference range.