01-07-2008, 06:41 PM
Chiu,
Have you considered introducing a LEM / SEM that supports bus (rather than star) wired sensors, supported by either a range of compatible sensors, and / or a module to fit inside off-the-shelf sensors.
In my last install there were 48 inputs (pretty much one per sensor type per room), and despite running multiple sensors on a single multicore cable where possible, it was still a lot of wire, and made cable management into, and in, the panels time consuming if nothing else, not to mention the additional complexity of wiring the sensors themselves to pass through unused wires to the next sensor. In addition, it meeant two full-size, and one smaller panel, and all this for a domestic installation.
With a bus wired system, depending on the design, it ought to be possible to run numerous sensors on a single two-wire loop (assumes the signalling is modulated on the power-line), or at most four wires if power and signalling are kept separate.
A disadvantage I can see is that a cable or sensor fault could disrupt some or all of the other sensors on the same bus, so it would still be appropriate to run multiple busses, either in a cable with more cores, and / or in conjunction with star wiring, but to a much lesser extent than with current designs.
In theory, comfort could support all 64 inputs (or more), on a single LEM added the the base panel.
The I/O module added to a sensor need be no bigger than a postage stamp judging by DCC modules. (What brought this back to mind was the purchase of a DCC model railway set for my kids, which allows independant digital powerline control of multiple trains on the same track - the train modules are measured in millimeters, and cost a few dollars to manufacture:
Thoughts any one?
Regards,
Matt.
Have you considered introducing a LEM / SEM that supports bus (rather than star) wired sensors, supported by either a range of compatible sensors, and / or a module to fit inside off-the-shelf sensors.
In my last install there were 48 inputs (pretty much one per sensor type per room), and despite running multiple sensors on a single multicore cable where possible, it was still a lot of wire, and made cable management into, and in, the panels time consuming if nothing else, not to mention the additional complexity of wiring the sensors themselves to pass through unused wires to the next sensor. In addition, it meeant two full-size, and one smaller panel, and all this for a domestic installation.
With a bus wired system, depending on the design, it ought to be possible to run numerous sensors on a single two-wire loop (assumes the signalling is modulated on the power-line), or at most four wires if power and signalling are kept separate.
A disadvantage I can see is that a cable or sensor fault could disrupt some or all of the other sensors on the same bus, so it would still be appropriate to run multiple busses, either in a cable with more cores, and / or in conjunction with star wiring, but to a much lesser extent than with current designs.
In theory, comfort could support all 64 inputs (or more), on a single LEM added the the base panel.
The I/O module added to a sensor need be no bigger than a postage stamp judging by DCC modules. (What brought this back to mind was the purchase of a DCC model railway set for my kids, which allows independant digital powerline control of multiple trains on the same track - the train modules are measured in millimeters, and cost a few dollars to manufacture:
Thoughts any one?
Regards,
Matt.
