BECKHOFF EP2xxx - Manual (Page 89)

Mounting and cabling
In some of the analog modules the sensors or actuators are supplied by Up ­ this means, for instance, that in
the case of 0...10 V inputs, any reference voltage (0...30 V) may be connected to Up; this is then available to
the sensors (e.g. smoothed 10 V for measuring potentiometers).
Details of the power supply may be taken from the specific module descriptions.
Attention
Electrical isolation may be cancelled!
If digital and analog fieldbus boxes are connected directly via four­core power leads, the
analog signals in the fieldbus boxes may be no longer electrically isolated from the control
voltage!
3.3.2 Status LEDs for power supply
Fig. 83: Status LEDs for power supply
LED display
LED Display Meaning
Us (Control voltage) off The power supply voltage Us is not present
green illuminated The power supply voltage Us is present
reed illuminated Because of overload (current > 0.5 A) the sensor supply
generated from power supply voltage Us was switched off for
all sensors fed from this.
Up (Auxiliary voltage) off The power supply voltage Up is not present
green illuminated The power supply voltage Up is present
EP2xxx 89 Version 2.1.0