DAQ Servers

The PADME DAQ system runs on a set of servers installed on a rack located in the BTF Experimental Hall 1.

l0padme4 and l0padme5

These are the front end nodes connected to the ADC boards via optical fibers. They run the DAQ and Zero Suppression processes.

l1padme1 and l1padme2

These are the on-line data server nodes ecah containing 17 TiB of RAID6 disk space. They run the Merger and Level1 processes. N.B. these nodes are visible from the LNF network with name l1padme3 and l1padme4 respectively.

l0padme1

This is the central DAQ system. It runs the RunControl, the Trigger and the DCS processes.

l0padme3

This node runs the Monitor system and some on-line reconstruction processes.

Network switches On top of the rack, a stack of three switches handles the network connections for the DAQ servers and the 10Gbps uplink to the LNF IT services.

Shut-down procedure

In case of programmed power cuts, it is important to switch off and unplug the rack hosting the DAQ system to avoid damages to the servers.

Servers must be turned off in the following order: l0padme3 - l1padme1 - l1padme2 -l0padme4 - l0padme5 - l0padme1

To turn off a server the user must physically connect the screen/keyboard/mouse located beside the rack to the desired node, then log in as daq and run the sudo shutdown now command. Please wait for each server to complete shutdown before proceeding to the next.

When all the servers are powered off, the power cables must be disconnected, i.e. all the plugs, including those of the network switches, must be unplugged from the horizontal power bars in the back of the rack.

Start-up procedure

The switch-on procedure for the DAQ system is the following:

1. Verify that the rack power lines are enabled and in stable conditions: check with BTF personnel.
2. Reconnect the power cables of all servers and switches to the two horizontal power bars in the back of the rack. As servers have redundant power supplies, make sure to connect the two cables to two different bars.
3. Verify that the network switches are up. At startup they need a few minutes to fully initialize: wait for the blinking leds in the top-left of each module to stabilize before proceeding.
4. Turn on the DAQ servers in the following order: l0padme1 - l0padme4 - l0padme5 - l1padme1 - l1padme2 - l0padme3.

To start a server the user must physically connect the screen/keyboard/mouse located beside the rack to the desired node, then push the power button located on the front panel of the node (exact location depends on the node type: look for the usual "Power button" symbol). Make sure each server has successfully completed the boot procedure (can take several minutes) before starting the next one.