thermal interoperability is defined as the ability for a compliant shelf to adequately cool a compliant blade. to achieve this, it is necessary to match the thermal and airflow characteristics of shelf slots and blades. an atca shelf has the responsibility of providing a minimum airflow and pressure performance in each slot. a compatible blade is required to utilize available shelf airflow effectively for cooling devices mounted on the blade.

to facilitate the thermal interoperability of both the shelf and blade it is necessary to characterize them independently using a standard test process and standard tools.  the test method and tools must accurately measure the flow through the chassis slots as well as the impedance of the boards and should be able to simulate a variety of conditions automatically.

degreec, in conjunction with cp-ta, developed tools for airflow characterization of atca shelf (chassis scan), and to determine airflow impedance of atca blades (blade profiler)

chassis scan

the chassis scan system consists of four types of modules that fit into atca front and rear slots. two of these modules have airflow sensors in them, namely, the front flow measurement board (ffmb) and the rear flow measurement board (rfmb). the other two modules, flow impedance boards for front and rtm slots (ffib and rfib, respectively), are matched impedance modules. all modules contain a mechanism to straighten the airflow at the intake and exhaust. the impedance of the ffmb and rfmb are equivalent to the ffib and rfib.

a pc based software reads airflow data from ffmb and frmb to store and analyzes the data. it also generates a test report that complies with cp-ta icd and tpm.

the chassis scan system comes with two shippable carrying cases; one that holds all 32 boards and necessary cables. the other includes the atm2400 airflow measurement hub, software and user manual.

the blade profiler is a wind tunnel specifically designed to mimic an atca slot of shelf and measure the impedance presented by the blade.

it has several airflow sensors that measure linear flow distributed across the channel. a sensor measures the pressure drop across the blade. the fan speed can be varied to generate different airflow level by the pc.

the pc application determines the flow impedance by varying fan speed and measuring the airflow and pressure drop.

the blade profiler instrument is shipped in its shippable carrying case.

the flow distribution across the blade is measured by the array of sensors. airflow levels seen by the quadrants are plotted. this enables the blade designer in evaluating component placement to address flow blockage and heat dissipation.

in an open architecture, such as atca, proper interoperability between modules determines the commercial success of the platform. interoperability is required for all interfaces between modules from mechanical fit, electrical power and signal integrity, inter-module communications protocol compliance, to thermal compatibility. communications platform trade association (cp-ta) developed interoperability compliance document (icd) as a guideline to enable interoperability of atca modules such as shelves and blades.

for more information visit http://www.degreec.com