LEDs INTF, 5 VDC, 24 VDC
Table 3-2
LEDs INTF, 5 VDC, 24 VDC
LED
Color
Meaning
INTF
Red
Lights up in the event of an internal fault
5 VDC
green Lights up as long as the 5 V voltage is within the tolerance limits
24 VDC
green Lights up as long as the 24 V voltage is within the tolerance limits
LEDs BAF, BATTF
Power supply modules with a backup battery have the following indicators:
Table 3-3
LEDs BAF, BATTF
LED
Color
Meaning
BAF
Red
Lights up if the battery voltage on the backplane bus is too low and the
BATT.INDIC switch is at the BATT position
BATTF
Yellow Lights up if the battery is empty, if the polarity is reversed, or if the battery
is missing, and the BATT.INDIC switch is at the BATT position
LEDs BAF, BATT1F, BATT2F
Power supply modules with two backup batteries have the following indicators:
Table 3-4
LEDs BAF, BATT1F, BATT2F
LED
Color
Meaning
BAF
Red
Lights up if the battery voltage on the backplane bus is too low and the
BATT.INDIC switch is at the 1 BATT or 2 BATT position
BATT1F
Yellow Lights up if battery 1 is empty or if the polarity is reversed or if the battery
is missing, and the BATT.INDIC switch is at the 1 BATT or 2 BATT position
BATT2F
Yellow Lights up if the battery 2 is empty, if the polarity is reversed, or if the battery
is missing, and the BATT.INDIC switch is at the 2 BATT position
Backup voltage to the backplane bus
The backup voltage is either supplied by the backup battery or fed externally into the CPU or
receiver IM. In its normal state, the level of the backup voltage is between 2.7 V and 3.6 V.
The backup voltage is monitored at the lower limit. Violation of the lower limit is indicated by
the BAF LED and reported to the CPU.
Power supply modules
3.4 Operator controls and indicators
S7-400 Automation System Module Data
46
Reference Manual, Ausgabe 11/2016, A5E00850736-08