GB2361792A

GB2361792A - In-line interface box for alarm system

Info

Publication number: GB2361792A
Application number: GB0010054A
Authority: GB
Inventors: Kenneth O'hara
Original assignee: Microcellular Systems Ltd; HARA KENNETH O
Current assignee: Microcellular Systems Ltd; HARA KENNETH O
Priority date: 2000-04-25
Filing date: 2000-04-25
Publication date: 2001-10-31
Also published as: GB0010054D0

Abstract

An interface box allows the collection of alarm information from unmonitored equipment with a remote alarm port that uses relay connections, e.g. a distributed antenna system, by a piece of monitored equipment with user definable alarm voltage sensitive inputs, e.g. a base station subsystem. Thus, the alarm status of the distributed antenna system can now also be monitored. A range of connectors can be used but, as a matter of preference, a D-type 9-pin male and female are chosen. The interface is based on a TTL logic chip 6 consisting of NOT gates 10. The number of NOT gates used determines the voltage presented to the voltage sensitive input of the monitored equipment. Thus any alarm condition can be covered.

Description

1 2361792 In-line Interface box The invention relates to an in-line

interface box for use with monitored equipment.

Certain types of monitored equipment provide user definable alarm ports. These ports are voltage sensitive. It is desirable to utilize these ports for the purpose of monitoring other equipment with remote alarm Ports, used in conjunction with the monitored equipment. For example, using a base station subsystem monitored by an operations and maintenance center to monitor its' own distributed antenna system.

The object of this invention is to provide an interface between the equipment to be monitored and that equipment which already is, in order to allow the operation and maintenance center monitoring the equipment to also monitor the additional equipment. There is a requirement that the alarm interface of the equipment that is to be monitored in this way, to be of a relay type, and to provide a DC voltage source.

Accordingly, this invention provides a means to collect alarm information ftom equipment and present it to the user definable alarm ports of the already monitored equipment. The interface comprises of a pair of resistors and a TTL logic chip made up of a series of NOT gates. Insulated copper wire is also used.

The components of the circuit can either be through mounted onto a piece of copper stripped veroboard, or surface mounted on a properly laid out PCB, and soldered into place. The ratio of the two resistors is adjusted to provide the required Vcc to the TTL chip. In some cases the resistors may not be required. The assembled circuit is contained within a box, plastic or metal, with two external ports. These ports are preferably Dtype, but can also be RJ-type, or a combination of the above. The interface is connected to the equipment using cables with the appropriate connectors to connect with the box on one end, and the connectors required to connect with the equipment on the other.

A preferred embodiment of the invention will now be described below with reference to the following figures:

Figure 1 shows the circuit diagram of the alarm interface as it would be connected to a piece of equipment to be monitored and to the monitored equipment.

Figure 2 shows the side of the box with the preferred D-type 9-pin male connector, for connection to the equipment to be monitored.

Figure 3 shows the side of the box with the preferred D-type 9-pin female connector, for connection to the monitored equipment.

Figure 4 shows an angled view of the box.

2 As shown in figure 1, an example is taken where a relay interface 4 is representative of the remote alarm interface of the equipment to be monitored. Port 2 is representative of the required DC power source. For the monitored equipment, port 11 represents the voltage sensitive user definable alarm port of the monitored equipment.

All the equipment in question must have a common ground. Thus all the ground pins 1,9 are connected together at the Vss pin of the TTL chip.

To power the TTL chip, the required DC voltage is attained by use of a simple voltage divider setup using two resistors 7,8. The required DC voltage is read from the spec sheet of the chip, and attained from the DC source 2 by adjusting the ratio of values between these resistors 7,8. The resulting voltage is then fed from the node between resistors 7 and 8 to the Vcc pin of the TTL chip, and also the input port 3 of the alarm relay 4.

Under non-alarm conditions, for this example, the relay connection 4 remains closed. For a non alarm condition to be monitored on the user definable input of the monitored equipment, in this example, requires a voltage high input. Thus the voltage at the node between resistors 7 and 8 is fed through the relay and into the input of a NOT gate. The resulting output of the NOT gate is inverted to the input of Vss, in this case, OV.This is again fed back into another NOT gate. The output of which is fed into the voltage sensitive user definable alarm pin of the monitored equipment.

This can be used for any number of alarm interfaces, as long as there is sufficient numbers of NOT gates on the TTL chip chosen, and a sufficient number of user definable alarm ports available on the monitored equipment. The use of this logic chip allows all combinations of the alarm variables to be covered, by varying the number of NOT gates 10 used. For example, open latch non-alarm condition on the non-monitored equipment with a voltage high non-alann condition required on the monitored equipment. In this case only one NOT gate 10 would be used as a straight inversion is all that is required.

Figure 2 shows the preferable connection to the equipment to be monitored, a D-type male connector 13. The pins on this are again connected to the appropriate components of the circuit, depending again on the cable connection between the interface box and equipment to be monitored.

From figure 3, the port on the box that connects to the user definable alarms is preferably a D-type female connector 12. The pins on the back of the connector are connected to the appropriate components in the circuit, depending on the cable connection used to connect to the monitored equipment to the interface box.

Claims

Claims

1 An interface box comprising of an input port, to be connected to the equipment to be monitored, and an output port, to be connected to the monitoring equipment, with a suitably designed circuit to convert the signals between the items of equipment, all contained within a box. 2 An interface box as in Claim 1, wherein the converting circuit uses logic gates to perform the interface. 3 An interface box as in Claim 2, wherein the logic gates used are NOT gates, also known as inverters. 4 An interface box as in any of the preceding claims, where at least one of the ports is a D-type connector. 5 An interface box as in Claim 1, Claim 2 or Claim 3, where at least one of the ports is an RJ 45 connector. 6 An interface box as in any of the preceding claims, used to interface between distributed antenna systems, and InterWAVE Communications equipment. 7 An interface box as in any of the preceding claims used to interface between distributed antenna systems, and interWAVE Communications equipment, for the purpose of monitoring alarm states. 8 An interface box as in any of the Claims 1 to 5, used to interface between an active distributed antenna systems, and InterWAVE Communications equipment. 9 An interface box as in any of the Claims 1 to 5, used to interface between an active distributed antenna systems, and InterWAVE Communications equipment, for the purpose of monitoring alarm states.