Siemens SCALANCE MUM853-1 - Grounding Guidelines; Digital Input;Output Connection

Signal quality
During installation make sure that there is a good signal strength of > -73 dBm.
If the "Q" LED is lit permanently, the signal quality is good. For more detailed information,
refer to the section "LED display (Page28)".
Avoid large metallic objects in the immediate vicinity.
6.5 Grounding
Grounding for wall mounting
The device is grounded by the 󹪝xing screw via the unpainted eyelet, position see section "Device
view (Page22)".
In addition to grounding via the 󹪝xing screw, you can also ground the device using the
terminal block. The terminal is identi󹪝ed by the following symbol for the functional ground
, position see section "Terminals (Page27)". Connect the terminal of the device with as
short a cable as possible ≤ 150mm and with the required cross-sectional area to a grounded
part of the system.
If the device is mounted on a non-conductive base, grounding must be connected either via
the functional ground on the terminal block or via a grounding cable.
The grounding cable is not supplied with the device. Connect the paint-free surface of the
device to the nearest grounding point using the grounding cable.
Grounding when installing on a DIN rail / S7 mounting rail
The device is grounded via the rear of the device.
You can also ground the device via the terminal block. The terminal is identi󹪝ed by the
following symbol for the functional ground , position see section "Terminals (Page27)".
Connect the terminal of the device with as short a cable as possible ≤ 150mm and with the
required cross-sectional area to a grounded part of the system.
6.6 Digital input/output
The digital input and output are connected using a 2-pin plug-in terminal block in each case. Two
terminal blocks ship with the device.
NOTICE
Damage due to voltage being too high or too low
The voltage at the digital input/output must not exceed 30 VDC and not fall below -30 VDC,
otherwise the digital input/output will be destroyed.
Connection
6.6Digital input/output
SCALANCE MUM853-1
56 Operating Instructions, 03/2023, C79000-G8976-C650-05