Why does my LDP-C/CW 18/40/50-05 driver does not reach the full current of my external applied setpoint?

This driver series features a potentiometer which can be used to limit the maximum current in order to protect the laser diode. Please refer to the photo below for the position of potentiometer (red circle). The current limit can be increased by turning the potentiometer clockwise and decreased by turning it counterclockwise. Please read the manual for further details.

Another possibility is that the connection between the driver and the laser diode is not suitable. With long or to thin cables as a significant voltage loss occurs. Please keep in mind that the supply voltage should always be 1 V above the load which includes the cable connection. The supply voltage must be within the specifications of the driver and you can find further information in the manual.