What is Power-over-CrewNet?
Power-over-CrewNet (PoC) is a proprietary network protocol that carries operating voltage and current to CrewNet-compatible devices connected to the Control Unit via RJ-45 connections (Cat-5e or greater.) Control Units must receive AC power via the supplied power cord in order to operate and provide necessary PoC to connected CrewNet-compatible devices. In addition, PoC can be supplied to devices downstream from a locally powered CrewCom Hub or RT.
- RJ-45 Copper Ports - Use the supplied 15 ft. (4.6 m) Cat 5e cable, or your own Cat 5e (or greater) cable (up to 330 ft. (100 m) in length). Any CrewCom device connected to CrewNet via a Cat 5e (or greater) cable will receive PoC from the CU via the CrewNet port. In some situations, there may be too many connected devices or the cable lengths may be too long for the PoC to adequately power all devices, and this will be indicated with the NET PWR LED lighting red. In this case, one or more additional Pliant 48VDC power supplies must be used (PPS-48V-02 included with Hub; sold separately with all other devices).
- Fiber (Optical) Ports - For a fiber CrewNet port, a Single Mode Fiber cable (duplex LC connector) will be required (up to 32,800 ft. (10,000 m) in length). Any CrewCom device connected to CrewNet via fiber port must receive power via a Pliant 48VDC power supply (PPS-48V-02 included with Hub; sold separately with all other devices).
Powering Downstream Devices
In most cases, powering an RT and any daisy-chained RTs downstream via PoC is acceptable. However, depending on cable lengths and number of RTs in your CrewCom configuration, you may need to utilize the 48VDC power supply (PPS-48V, sold separately) to provide local power where needed. Under optimal conditions, seven connected RTs may be powered from a locally powered RT; however, this number can vary greatly depending on the line lengths and the number and configuration of those connected RTs.
To ensure best performance, especially with larger CrewCom configurations and longer cable lengths, Pliant recommends utilizing the supplied 48VDC power supply to locally power each Hub. However, powering a Hub and the devices connected to it via PoC may be advantageous in some smaller configurations.
Power for Fiber Devices
Fiber connections will not transfer power to a CrewCom device. For CrewNet-compatible devices using fiber connectivity, local power must be supplied to that device using a Pliant 48VDC power supply (PPS-48V-02 included with Hubs, sold separately for all other devices). Once local power is supplied to the device, downstream devices may receive power via PoC (subject to limitations, depending on the line lengths and the number and configuration of those connected devices.)