What are a Genius Terminal’s Power Requirements

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Cayan’s Genius terminals can be powered either via AC current or via Power Over Ethernet (PoE). Included in the table below are representative power requirements that Cayan observed in its lab for Verifone V4 hardware models, as would be deployed in a P2PE environment. The power requirements measured between AC and PoE tended to be within 1W of each other. The MX925 series was observed to have higher Wattage requirements, as it has a larger screen than a MX915. Please note that using PoE with your Cayan Genius terminal requires a specialized I/O block, available from Cayan and Verifone. Please reach out to your Sales Engineer to ensure that you receive the necessary equipment.
 
Terminal model boot  idle transactions
mx915 2-3W 2-3W 4-7W
mx925 3-4W 3-4W 6-9W

Power over Ethernet or PoE describes any of several standardized or ad-hoc systems which pass electric power along with data on twisted pair Ethernet cabling. This allows a single cable to provide both data connection and electric power to devices such as wireless access points, IP cameras, and VoIP phones.
 
The original IEEE 802.3af-2003 PoE standard provides up to 15.4 W of DC power (minimum 44 V DC and 350 mA) on each port. Only 12.95 W is assured to be available at the powered device as some power dissipates in the cable. The updated IEEE 802.3at-2009 PoE standard also known as PoE+ or PoE plus, provides up to 25.5 W of power for "Type 2" devices. The 2009 standard prohibits a powered device from using all four pairs for power. Both of these amendments have since been incorporated into the IEEE 802.3-2012 publication.
 
Employing Power over Ethernet brings several advantages to an installation:
  • Time and cost savings - by reducing the time and expense of having electrical power cabling installed.  Network cables do not require a qualified electrician to fit them, and can be located anywhere.
  • Flexibility - without being tethered to an electrical outlet, devices such as IP cameras and wireless access points can be located wherever they are needed most, and repositioned easily if required.
  • Safety - POE delivery is intelligent, and designed to protect network equipment from overload, underpowering, or incorrect installation.
  • Reliability - POE power comes from a central and universally compatible source, rather than a collection of distributed wall adapters.  It can be backed-up by an uninterruptible power supply, or controlled to easily disable or reset devices.
  • Scalability - having power available on the network means that installation and distribution of network connections is simple and effective.
If your environment provides insufficient power to the payment terminals, you may notice anomalous behavior, such as the terminals unexpectedly rebooting. Cayan recommends that all network engineers employ the following best practices when deploying payment terminals in a PoE environment:
  • Provide sufficient power to the remote powered device. This may sound simple, but in practice, it is difficult. The IEEE 802.3af standard identifies four possible power classifications. At maximum, the powered remote device can draw up to 12.95 watts of power. Factoring loss through the length of the cable, this means that, at maximum, the power-sourcing equipment must have the ability to provide 15.4 watts of power to each port. In a 24-port Ethernet switch or midspan device, this means that approximately 370 watts of power must be available to supply the necessary power to each port. For the Ethernet switches, additional power above and beyond that required for PoE must be available for its switching functions.
  • Provide sufficient power to the remote powered device – by ensuring that they’re plugged into the right ports. Many switches will offer several “tiers” of power to PoE devices – for example, they may offer both 4W ports and 15.4W ports. Many smaller devices (eg. web cameras or microphones/speakers) have lower power requirements than payment terminals. Ensure that your payment terminals are plugged into ports that support the power requirements outlined above.
  • Connect the power source to uninterruptible and redundant power. The remote devices fed by PoE typically are mission-critical devices. For instance, an IP phone that loses power is a lost voice circuit. Think about that for a moment. Regardless of whether it is a traditional circuit-switched analog phone or an IP phone, it is a lifeline circuit. It has to work. You must consider how you are going to design your network to ensure that consistent and reliable data transfer and power are maintained to this critical device. Connect the critical power-sourcing devices to an uninterruptible power supply, and use devices with dual redundant power supplies to ensure that your critical devices never lose power.
  • Pay attention to cabling-performance specifications. What Category rating does your cabling infrastructure have? Most likely, this is Category 5e or 6.
  • Pay attention to cabling length. PoE will only power the unit so long as there is enough voltage to power the unit at the end of the cable run. The maximum distance you can power a device will vary depending on the access point and its voltage required, as well as the voltage provided by the power supply, and the quality of the cable. Cat6 cable is recommended for long POE runs. For passive POE you should use a 24V power supply. 24V passive POE will power an OM series AP up to about 50 meters or 100-150 feet. 48V 802.3af standard POE can usually go about 100 meters/300 feet.