Figure 11: Location Of Ground Jumpers Bottom Side Circuit Board - Bosch AMC-4W Installation Manual

Installing the AMC-4W Access Controller AMC-4W
AMC-4W. The host system must not connect cable shield and protective
ground. If not using the ground conductor of the RS485 host interface, Jumper
2 should be set at every AMC-4W.
Setting jumper 3 connects the internal ground of the AMC-4W to the shield of
the RS485 host interface. Set Jumper 3 only at the first AMC-4W of a party
line. The host system must not connect cable shield and protective ground. If
the AMC-4W is set to RS232 mode, Jumper 3 must be set.

Figure 11: Location of ground jumpers bottom side circuit board

Jumper 4 connects the internal ground of the AMC-4W to the RS485 ground of
the slave interface. Jumper 4 shall only be set if the AMC-4W powers all other
peripheral devices which are directly connected to the AMC-4W.
24 Installation Guide Bosch Security Systems | V.3.1/2006-09