The pulsar board for the MAGIC-II telescope data acquisition system

The MAGIC telescope is the world´s largest gamma ray telescope, designed to look at the light emitted by air shower by Cherenkov effect. It is operating since 2004 at the Roque de Los Muchachos observatory, La Palma, Canary islands. MAGIC-II is the upgrade of the project, consisting of a twin telescope frame with innovative features like new photon detectors to lower the threshold energy further and an ultrafast signal sampling to reduce the effect of the diffuse night sky background. The new acquisition system is based upon a low power analog sampler (Domino Ring Sampler) with frequency ranging from 1.5 to 4.5 GHz. The data are digitized with a 12-bit resolution ADC. Data management is based on a digital board called PULSAR (PULSer And Recorder). Every board has 80 analog channels plus auxiliary digital signals for trigger and monitor purposes. The PULSAR board shows a good programming flexibility with the typical speed of a hardware device and an efficient modularity. The firmware controls the analog boards for the analog to digital conversion and it handles the data compression and reformatting. The data acquisition system design and the role of the PULSAR board is described in detail.