Installation manual

IOI-XTRK-10D Installation Manual
12
Power Sourcing Equipment 4.2.3.1.1
The power sourcing equipment (PSE) ensures that no damage can occur to any equipment on the
network. The PSE first looks for devices that comply with the IEEE 802.3af specification. This is
achieved by applying a small current-limited voltage to the cable. The PSE then checks for the
presence of a 25k ohm resistor in the remote device. If this load or resistor is detected, 48V is
applied to the cable, but it is still current-limited to prevent damage to cables and equipment under
fault conditions. The PSE will continue to supply power until the encoder (the powered device) is
removed or it stops drawing its minimum current.
The Encoder as a Powered Device 4.2.3.1.2
The encoder must be able to operate within the confines of the Power over Ethernet specification. It
receives a nominal 48V from the cable, and must be able to accept power from the spare twisted
pair or from data cables. Because the supplied 48 volts is too high to power the electronics, an
isolated DC-DC converter is used to transform the 48V to a lower voltage. This also enables 1,500V
isolation to be provided for safety reasons.
Power on Terminal Block Connector 4.2.3.2
Following is an illustration of the power connection on the unit’s front panel.
Figure 5 - Terminal Block Electrical Polarity
The power supply specification for the IOI-XTRK-10D is 12-24 VDC or 24 VAC.
Caution:
Always use a properly rated external power supply. Make certain the power
supply used meets the unit’s specifications.
Note:
The DSP chip embedded in the unit uses flash memory, which stores configuration
settings even when the unit is not powered.