RF Code, Raritan Launch System for Monitoring Server Power Consumption

By Claire Swedberg

The solution combines Raritan's power distribution units (PDUs) and RF Code's RFID sensor tags and readers, reducing the need for an Ethernet cable to forward energy-usage and environmental data to a company's back-end system.

RFID technology firm RF Code and power distribution unit (PDU) provider Raritan have developed a solution that combines Raritan's power distribution units and RF Code's RFID sensor tags and readers. The technology is a marriage of two previously disparate systems: Raritan's solution for measuring server power consumption, and RF Code's system for monitoring the temperature and humidity in the vicinity of those servers. The hybrid solution uses the RFID tags instead of an Ethernet cable to forward energy-usage and environmental data to a company's back-end system, thereby reducing the need for an Ethernet cable and the associated cost of installing and then maintaining that cable. The system employs RF Code's R170 PDU RFID sensor tag, developed specifically for this new solution, as well as Raritan's PX-1000 series of PDUs. The hybrid solution became commercially available this week.

Raritan's PDUs are designed to not only provide power to servers in data centers, but also to measure the consumption of power going to an individual server or group of servers, and then forward that information to a back-end server. Raritan's PX-1000 PDUs measure only inline power—that is, the power consumed by all servers to which a particular PDU is connected. The company's PX-5000 series, on the other hand, can receive instructions via the Ethernet cable, enabling users to switch off any server receiving power from that unit. In the case of the new hybrid RFID product, says Herman Chan, the director of Raritan's power-management business, the PDUs are versions of PX-1000 models that have been specially modified via its firmware to support communication by RFID instead of through an Ethernet cable.


Raritan's Herman Chan

In the past, Raritan has depended on Ethernet cabling to connect a PDU to a back-end system. This, however, can be expensive, says Chris Gaskins, RF Code's VP of product development. The cost per Ethernet port can be $300, he explains, which includes the Ethernet cable, a patch panel and an Ethernet switch, as well as installation labor; hundreds of ports are often installed in a typical data center. To add sensors to an existing wired Raritan PDU, the cost would start at $60 per sensor.

With the new hybrid solution, an RF Code tag is plugged (via an RJ12 connector) into a PX-1000 PDU supplying power to servers installed in a rack. When the PX-1000 measures current and/or kilowatts per hour being consumed by all of the servers, it sends that information to the 433 MHz active RFID tag. The tag then forwards that energy-consumption data every 10 minutes, along with its own temperature and humidity sensor data, to an RFID reader known as an RF Code Zone Manager, located at a central point in the data center (typically, one or two readers are sufficient to cover an entire data center, since each interrogator can cover from 2,000 to 5,000 square feet). The reader then transmits that information to the data center's server via an Ethernet connection.

Many data centers currently in operation employ what are known as "standard" or "basic" PDUs, which function as dumb power strips and do not measure energy consumption. (Raritan does not sell these sorts of PDUs.) What makes the Raritan-RF Code solution attractive for many basic PDU users, Chan notes, is the opportunity to upgrade to a metered solution without the need for an Ethernet cable connecting the PDU with the back-end system. He predicts that a large majority of those currently utilizing standard PDUs will transition to a metered solution to track power consumption, and find ways to reduce their carbon footprint and increase efficiency.

Wireless solutions, Chan says—such as the RF Code-Raritan system—offer a way to do so at a much lower cost. RF Code tags, which include built-in temperature and humidity sensors, list at $100 apiece, while a single RFID reader, which can support as many as 40 server racks, costs $1,245. Therefore, a typical price for the wireless connection would be, on average, $240 per rack, or $24,000 for a center with 100 racks, including the expense of tags, readers, sensors and labor. The typical cost of a wired option, on the other hand, would be $300 for each cabled connection, plus $60 per sensor, for an average of $360 per rack, or $36,000 for a center with 100 racks—assuming only one PDU (and thus, one cable connection) per rack.

The system was developed earlier this year, Chan says, at the suggestion of an end user that had been employing an RF Code system and hoped to add power metering from Raritan, and had thus suggested a combined solution. That customer, he says, which has asked to remain unnamed, has now approved samples of the technology and intends to install the RFID-enabled power-metering system at its own data center.

"Our next step," Chan states, discussing Raritan's partnership with RF Code, "is to work out joint sales programs" that would allow either or both of the companies to market the combined product—though each technology is sold separately through distributors, Gaskins notes, many of which sell both products.

Raritan plans to RFID-enable its PX-4000 series of PDUs, which support the metered tracking of each of its power outlets—and, thus, the energy consumption of the specific server plugged into each outlet. The necessary PX-4000 firmware, as well as any hardware upgrade, will be available in the near future, Chan says. If multiple outlets are being used and a customer has purchased a PX-4000 series PDU, then information regarding current and kilowatt per hour for each server will be transmitted to the RFID tag. Because RF Code's RFID system is unidirectional (that is, capable of transmitting data only from the tag to the reader, and not vice versa), Raritan's PX-5000 series of switched PDUs will not work with the RFID technology, and must instead be installed with an Ethernet cable, which supports bidirectional communication.

Raritan and RF Code intend to offer a seminar for potential customers later this year, Chan says, to describe how the system can save them money. "I think it's a pretty important issue in data centers," he states. "For those using basic PDUs, they don't have to worry about installing a network [of additional Ethernet cables]. Besides saving the cost of equipment, the labor to install it is reduced, and the time to get it up and running is reduced."