Hirschmann BAT450-F User Manual page 24

The socket housing is electrically connected to the housing of the device.
The V.24 interface is not electrically isolated from the supply voltage.
You can use the V.24 interface to connect the AutoConfiguration Adapter
ACA11 storage medium.
The AutoConfiguration Adapter ACA21-M12 and ACA22-M12 storage media
are incompatible with the device.
Figure
Table 4: Pin assignment of the V.24 interface (M12 socket)
24
Pin Function
1 TX Transmit Data
2 RX Receive Data
3 N.C. Not used
4 GND Ground
Installation BAT450-F
Release 06 08/2017