The RP controller expansion modules have digital inputs that can be used for sensing of dry contacts:
The light modules, blind modules, and the RP-C-EXT-REL-4 relay module have four digital inputs, which can be used in applications such as interfacing with light switches and window contacts.
The CRS-HH-REL-10 relay module has 12 digital inputs suitable for dry contact monitoring of switches and push buttons used for lighting control, window and door positions, and other functions in the hotel room.
The external connection of a digital input is shown in the following figure:
K is the monitored external switch.
V S = 5 V
R PU = 2.2 kohm
Be careful when connecting the digital inputs. When connecting the digital inputs to dry contact relays, the relays must be galvanically isolated from everything else. You can use a common wire from RET to all dry contact relays connected to the same RP controller expansion module. Do not connect RET from one RP controller expansion module to anything else, including RET/G0 of another RP controller expansion module or RP-C controller. The digital inputs may be connected to open collector outputs provided that the open collector outputs belong to circuits that are galvanically isolated from everything else.
If a RET terminal of one RP controller expansion module is connected to RET/G0 of another part of the system, it can cause problems in case there is an interruption in the G0 supply somewhere in the system. This is because the system may get its G0 connection maintained by the ground connection through the room bus (RS-485) interface, which is not designed for such a high current. This means that connection of RET of an RP controller expansion module to any part that is not galvanically isolated from everything else can damage the room bus (RS-485) interface.
Light modules, blind modules, and RP-C-EXT-REL-4 | |
Inputs
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4, DI1 to DI4
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Range
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Dry contact, 0 to 5.0 VDC, 2.2 mA, SELV (Safety Extra-Low Voltage)
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CRS-HH-REL-10 | |
Inputs
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12, DI1 to DI12
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Range
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Dry contact, 0 to 5.0 VDC, 2.2 mA, SELV (Safety Extra-Low Voltage)
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