Rittal rack design
The water cooled Rittal racks are composed of two rack units sharing one Liquid Cooling Package LCP
The racks are on the right and on the left side of the LCP unit.
On the back side ( warm air side
), the LCP unit pulls the warm air and pushes it through the heat exchanger to the front side ( cold air side
CMC TC unit rack
The two racks are controlled by the so called [ CMC TC control unit | CMC control unit ].
Two of the ports of the control unit are occupied with IO units, one for each rack.
The ports of each IO unit are entire used with two relays, one temperature sensor and one door sensor.
The relays are used to switch on and off the rack and prevent the rack from overheating.
CMC basic LCP
The CMC control unit in the LCP unit is responsible for recording the temperature of the water in- and outgoing water, the temperatures of in- and outgoing air on three positions and the water flow rate.
Additionally a smoke detector is connected with one of the ports. The CMC unit controls the water valve and the fan speed.
manipulating the racks
The racks can be switched on and off by using the CMCctrl
perl script which is currently placed in ~loki/hancluster/Racks/Racks_Rittal/Administration
on the 22.214.171.124
CMCctrl -h shows further options. Switching the racks on works with CMCctrl -r 3-9,12,17 -on
which switches on the racks 3 to 9, 12 and 17, respectively.
CMCctrl -r .... -all
monitors the temperature and reports an open door.
Furthermore, it monitors the status of the relays.
If the first relay is in the off state and the second is in the on state the rack is in the normal state. Unfortunately, it is not sure whether the rack is has power or not since the racks just keeps its current status. Hence, in the case of an antecedent over-temperature, the rack stays off. If the first relay is in the on
state, the racks
is surly on. If both relays are in the off
state the rack is surly off. This state can be achieved by
using CMCctrl -r ... -offcourseoff
status of the LCP
The status of the LCPs can be monitored by using the perl script CMC_Basic_ctrl
options determines the LCP unit, e.g., CMC_Basic_ctrl -l 2-7,9
handles the LCP units from 2 to 7 and 9 respectively.
The option -all
shows several values as the 3 temperatures of the in- and 3 temperatures of the outgoing air. It shows the amount of heat
that is carried away, the flow rate of the water, the valve status and the temperatures of the in- and outgoing water.