Bosch Access Modular Controller 2, Installation Manual

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Access Modular Controller 2 Installing | en 19
Bosch Security Systems B.V.
Installation manual
2021-04 | V04 | IM
4.6 Grounding and shielding
The main grounding point at the controller is connected to pin 2 of the power supply
connector - see Connecting diagrams.
It is good practice to shield all wires carrying low level signals.
The controller allows you to create a central ground or shielding point, simply by setting
certain jumpers. Set these jumpers only if grounding or shielding is not achieved by other
means.
i
Notice!
Risk of malfunction
Ensure that no ground loops are formed.
i
Notice!
In general the following apply:
If the devices have their own power supplies, the shielding is applied to one side only. The
free end should be insulated to avoid inadvertent connections.
If one device is fed power by another, the cable shielding should be applied to both sides.
4.6.1 Grounding for Host Interface
A 1:
A 2:
A 3:
Delivery status
JP1
JP2
JP1
JP2
A
Figure 4.5: Location of ground jumper RS-485 host interface
The internal ground of the controller is always connected with the ground of the RS485 host.
The jumper setting A1 shows the factory settings.
Jumper JP1 connects the internal ground of the controller to the ground of the RS-485 host
interface.
Jumper JP2 manages the signal ground.
Settings for jumper JP1:
If the ground conductor and the shield on the host are not connected and:
–
no party line exists, the jumper JP1 is set (= A2)
– a party line exists, the jumper JP1 is set at the first device only (= A2)
Settings for jumper JP2:
If the ground conductor and the shield on the host are not connected and:
–
no party line exists, the jumper JP2 is set (= A3)
– a party line exists and signal ground is connected, the jumper JP2 is set at the first device
only (= A3)
– a party line exists and signal ground is not connected, the jumper JP2 is set at all devices
(= A3)