Access control apparatus and method therefor
An apparatus includes an AC-to-DC power supply, with a positive terminal operatively coupled to two two-wire pairs of an Ethernet port to provide a first and second power path over a structured cable. A negative terminal is operatively coupled to a third two-wire pair of the Ethernet port to complete the first power path. Power path control logic has an input port operative to receive a two-wire input signal from an external device, and is operatively coupled to the negative terminal of the AC-to-DC power supply output, and to a fourth two-wire pair of the Ethernet port to complete the second power path. The power path control logic is operative to disconnect the negative terminal of the AC-to-DC power supply from the fourth two-wire pair of the Ethernet port in response to a two-wire input signal received at the input port, to disconnect the second power path.
1. An apparatus comprising:
an AC-to-DC power supply, having a positive terminal operatively coupled to two two-wire pairs of an Ethernet port to provide a first power path and a second power path over a structured cable, and a negative terminal operatively coupled to a third two-wire pair of the Ethernet port to complete the first power path; and
power path control logic, comprising:
a control circuit;
an input port, operatively coupled to the control circuit, operative to receive a two-wire input signal from an external device and provide the two-wire input signal to the control circuit; and
a controllable switch, operatively coupled to the control circuit, the controllable switch operative to disconnect the negative terminal of the AC-to-DC power supply from a fourth two-wire pair of the Ethernet port in response to a control signal from the control circuit, to disconnect the second power path, the controllable switch comprising:
an input to receive the control signal from the control circuit;
a first switch terminal operatively coupled to the negative terminal of the AC-to-DC power supply output; and
a second switch terminal operatively coupled to the fourth two-wire pair of the Ethernet port to complete the second power path.
2. The apparatus of claim 1 , where the two-wire input signal from the external device is provided by the external device as an output type selected from the group consisting of: a normally-closed (NC) relay contact output, a normally-open (NO) relay contact output, and a continuous voltage (C) output.
3. The apparatus of claim 1 , where the two-wire input signal from the external device is a fire alarm input (FAI) signal and the external device is a Fire Alarm Control Panel (FACP).
4. A system comprising:
an AC-to-DC power supply, having a positive terminal operatively coupled to two two-wire pairs of an Ethernet port to provide a first power path and a second power path over a structured cable, and a negative terminal operatively coupled to a third two-wire pair of the Ethernet port to complete the first power path; and
power path control logic, comprising an input port operative to receive a two-wire input signal from an external device, the power path control logic operatively coupled to the negative terminal of the AC-to-DC power supply output, and to a fourth two-wire pair of the Ethernet port to complete the second power path, the power path control logic operative to disconnect the negative terminal of the AC-to-DC power supply from the fourth two-wire pair of the Ethernet port in response to a two-wire input signal received at the input port, to disconnect the second power path;
a power-over-Ethernet splitter, operatively coupled to the apparatus by a structured cable, the splitter comprising:
a splitter Ethernet port for connecting to the structured cable;
a first DC-to-DC convertor, operatively coupled to two two-wire pairs of the splitter Ethernet port to receive power from the first power path over the structured cable;
a second DC-to-DC convertor, operatively coupled to another two two-wire pairs of the Ethernet port to receive power from the second power path over the structured cable;
an Internet protocol (IP) access control circuit, operatively coupled to the splitter to send IP data to, and receive IP data from, the apparatus, operatively coupled to the first DC-to-DC convertor to receive system power from the first power path, and operatively coupled to the second DC-to-DC convertor to receive lock power from the second power path used to maintain a locking device in a locked position, the IP access control circuit operative to cause the locking device to be placed in an unlocked position in response to disconnection of the second power path by the apparatus.
5. An apparatus comprising:
an Ethernet port, comprising a first, second, third and fourth transformer, each transformer corresponding to an Ethernet cable pin pair and operative to provide a data connection to a remote power-over-Ethernet powered device via a structured cable;
an AC-to-DC power supply, having a positive terminal operatively coupled to a secondary center-tap of the first transformer and the third transformer, and a negative terminal operatively coupled to a secondary center-tap of the second transformer to provide a first power path using the first transformer and the second transformer; and
power path control logic, comprising:
a control circuit;
an input port, operatively coupled to the control circuit, operative to receive a two-wire input signal from an external device and provide the two-wire input signal to the control circuit; and
a controllable switch, operatively coupled to the control circuit and operative to disconnect the negative terminal of the AC-to-DC power supply from the fourth two-wire pair of the Ethernet port in response to a control signal from the control circuit, the controllable switch comprising:
a first switch terminal and a second switch terminal, where the first switch terminal is the power path control logic first terminal and is operatively coupled to the negative terminal of the AC-to-DC power supply output;
a second switch terminal, where the second switch terminal is the power path control logic second terminal and is operatively coupled to a secondary center-tap of the fourth transformer to provide a second power path using the third transformer and the fourth transformer.
6. The apparatus of claim 5 , where the two-wire input signal from the external device is provided by the external device as an output type selected from the group consisting of: a normally-closed (NC) relay contact output, a normally-open (NO) relay contact output, and a continuous voltage (C) output.
7. The apparatus of claim 5 , where the two-wire input signal from the external device is a fire alarm input (FAI) signal and the external device is a Fire Alarm Control Panel (FACP).
8. A system comprising:
an Ethernet port, comprising a first, second, third and fourth transformer, each transformer corresponding to an Ethernet cable pin pair and operative to provide a data connection to a remote power-over-Ethernet powered device via a structured cable;
an AC-to-DC power supply, having a positive terminal operatively coupled to a secondary center-tap of the first transformer and the third transformer, and a negative terminal operatively coupled to a secondary center-tap of the second transformer to provide a first power path using the first transformer and the second transformer; and
power path control logic, comprising:
a first terminal operatively coupled to the negative terminal of the AC-to-DC power supply output;
a second terminal operatively coupled to a secondary center-tap of the fourth transformer to provide a second power path using the third transformer and the fourth transformer; and
an input port operative to receive a two-wire input signal from an external device, where the power path control logic is operative to disconnect the negative terminal of the AC-to-DC power supply from the secondary center-tap of the fourth transformer, thereby disconnecting the second power path from the remote power-over-Ethernet powered device, in response to the two-wire input signal received at the input port;
a power-over-Ethernet splitter, operatively coupled to the apparatus by a structured cable, the splitter comprising:
a splitter Ethernet port for connecting to the structured cable, the splitter Ethernet port comprising a fifth, sixth, seventh and eighth transformer, each transformer corresponding to an Ethernet cable pin pair and operative to provide a data connection to the apparatus via the structured cable;
a first DC-to-DC convertor, having a positive input operatively coupled to a primary center-tap of the fifth transformer, and a negative input operatively coupled to a primary center-tap of the sixth transformer, to receive power from the first power path over the structured cable;
a second DC-to-DC convertor, having a positive input operatively coupled to a primary center-tap of the seventh transformer, and a negative input operatively coupled to a primary center-tap of the eight transformer, to receive power from the second power path over the structured cable; and
an Internet protocol (IP) access control circuit, operatively coupled to the splitter to send IP data to, and receive IP data from, the apparatus, operatively coupled to the first DC-to-DC convertor to receive system power from the first power path, and operatively coupled to the second DC-to-DC convertor to receive lock power from the second power path used to maintain a locking device in a locked position, the IP access control circuit operative to cause the locking device to be placed in an unlocked position in response to disconnection of the second power path by the apparatus.