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Powering via CAT5 spare pairs

The SiteMonitor Unit is not capable of standard PoE operation. Power is typically provided via cabling separate from the Ethernet link.

However, in certain circumstances, it may make sense to be able to power the SiteMonitor using the same cable which is also used to connect the unit to the Ethernet Switch. This is possible, but requires special wiring.

You will need CAT5 termination tools (crimper, stripper, etc) and RJ45 ends, along with suitable CAT5 cabling.

  1. On the SiteMonitor end, strip approximately 4-6 inches of the outer jacket from a CAT5 cable, leaving the inner wires unharmed.
  2. Leaving the 6-8 inches of wire, Terminate the Ethernet Pairs in a RJ45 end, in the normal position. This is pins 1, 2, 3, and 6, and typically wire colors White/Orange, Orange, White/Green and Green (for 568A wiring). You will end up with a RJ45 connector crimped directly onto the pairs of wire, without an outside jacket. This connector will be slightly more fragile than a normal connector, so be careful when inserting and removing.
  3. With the remaining two pairs (Brown and Blue), strip the ends of all four wires. These will be connected to the base unit's terminal block. Twist both of the Brown wires together, and do the same for the Blue wires.

Where you connect the remaing two pairs is determined by how you inject power onto the CAT5 cable.

  • If you use a standard Motorola Canopy power supply, or other PoE injector (up to 24V) which provides + on the brown pair, and - on the blue pair: connect both blue wires to the - terminal of PWR1 or PWR2, and both brown wires to the + terminal of the same PWR input.
  • If you use a PoE injector (up to 24V) which provides + on the blue pair, and - on the brown pair: connect both blue wires to the + terminal of PWR1 or PWR2, and both brown wires to the - terminal of the same PWR input.
  • Alternatively, you can make the other end of the Ethernet cable identical to the SiteMonitor End - that is, with the power pairs split out from the Ethernet pairs, and then connect the spair pairs to your power supply. In which case, you can use either the blue pair or brown pair for +. Just be sure to make sure that the + side of your power supply is connected to the + terminal on the PWR input you use.

Regardless of how you inject the power, we recommend that you use a voltmeter to confirm voltage and polarity *before* plugging the terminal block into the base unit.