IGW Power over Ethernet

Objective

This document presents details on the Power over Ethernet support for the Volterra Industrial Gateway (IGW) 5000 and 5500 series.

Volterra hardware supports both POE (802.3af) and POE+ (802.3at).

Type Details
POE Power Over Ethernet
802.3af
15.4W max at Power Sourcing Equipment (PSE) - Volterra hardware
12.95W max at Power Device (PD) - Customers’ poe device such as camera and sensors
POE+ Power Over Ethernet plus
802.3at
30W max at Power Sourcing Equipment (PSE) - Volterra hardware
25.5W max at Power Device (PD) - Customers’ poe device such as camera and sensors

IGW 5000 and 5500 Series POE Power Budget

Property Details
Total power budget 64.8W
Guard band 3W
Available power 64.8-3=61.8W
Power management mode Dynamic (measured and calculated in real time)
Port priority All ports have equal priority with power allotment on a first come, first-served basis.

Note: IGW requires an external POE PSU.

IGW 5000 and 5500 Series POE Power Management

The total power budget for POE on the IGW is 64.8W with a guard band of 3W. Power consumption for each port is measured and calculated dynamically in real-time. Each port receives power on a first come, first-served basis.

The following scenarios explain the power management operation:

  1. 4 POE devices connected to the POE ports on the IGW and they all draw 15Ws each.

    • Total calculated power draw = 15+15+15+15= 60W
    • Power Available = 61.8W
    • All four devices will be provided power as needed
  2. 2 POE+ devices connected to the POE ports on the IGW and they both draw 25Ws from the IGW. A third device is now connected drawing 15Ws.

    • Total calculated power draw after the third device is connected = 25+25+15=65W
    • Power Available = 61.8W
    • Third device will not be powered up.
    • First two devices continue to be provided power as needed
  3. 4 POE+ devices connected to the POE ports on the IGW and they all draw 15Ws in steady state from the IGW. Now device on port 3 is disconnected and replaced with another device that requires 25W from the IGW

    • Total calculated power draw = 15+15+15+25=65W
    • Power Available = 61.8W
    • Device on port 3 will be powered down
    • Devices on port 0,1,2 will be provided power as required.
  4. Following-on to scenario 3, if device on port 3 is replaced with a device that draws only 15W, then the calculated power draw from the IGW will be 60Ws which is less than Power Available (61.8W) and therefore device on port 3 will be supplied power as required.