Diagnostics per channel

Open Load (Index 0x60n1:02)

The open load detection shows that no load is connected when the output is switched on.

The “open load” bit (index 0x60n1:02) is set to TRUE if the output is TRUE and the output current is less than typ. 0.2 mA.

Short Circuit to 24V (Index 0x60n1:04)

A short circuit to 24 V is detected if the output is FALSE, but nevertheless a voltage of more than typ. 10 V is present. The “Short Circuit to 24V” bit (index 0x60n1:04) is set to TRUE. The corresponding LED flashes red.

Overtemperature (index: 0x60n1:01) – overcurrent (index:0x60n1:03)

The “Overcurrent” bit (index: 0x60n1:03) is set in case of an overload. The LED lights up red. The channel heats up, so that the “Overtemperature” bit (index: 0x60n1:01) is set on reaching an upper limit temperature (see fig. Overload current limitation).

In the case of a short-circuit the channel overheats very quickly, leading to it being switched off. Once the temperature has cooled down to below a lower limit value following the switch-off, the output is switched on again. The temperature, however, is then still so high that the “Overtemperature” bit (index: 0x60n1:01) remains set. Thus the LED remains red as long as the short-circuit is present.
Overcurrent diagnostics is no longer possible once the output is switched off. The “Overcurrent” bit (index: 0x60n1:03) is only set to TRUE when the output is switched on again (see fig. Schematic illustration of the thermal switch-off in case of overload).