A very productive engineering night: First, succesful testing of network DNS dependences for DECam. After, succesful addition of a new feature to the guider interface.

About the DNS tests: we realized that the previous tests (previous night) had included the SOAR DNS as a tertiary DNS (which is the default configuration during operations), so we removed this dependence and performed several tests again with and without the Tololo DNS and/or La Serena DNS. As a summary, we realized that the DECAL machine (Windows) did not have a local host table and SISPI failed if both DNS were down. This problem was quickly fixed by B. Malet and we could confirm that DECam works normally if there are no DNS available. This means that DECam machines and the network now have the desired configuration and the system performs well if DNS fail or recover even in the middle of exposures. We also tested Rasicam and confirmed that telemetry was available in Las Tacas if La Serena and Tololo DNS were down. Thanks to Mauricio Rojas, Bernardo Malet, Eduardo Toro, Petri Garagorri, Chris Morrison (and ITOps in general), Diego Gomez, Marco Bonati and Omar Estay for all the work to achieve this.

After the network tests were finished, Diego Gomez and I took advantage of the remaining engineering time and added a much-needed feature in SISPI: a function to modify the guider exposure time DURING an exposure. Before this, any change to the guider exposure time took place for the next exposure (impacting narrow-band observations specially, as they use longer exposure times), but now it is possible to increase the guider exptime to recover guiding if it fails. I will send a separate email with the details of the new feature to the sci-support and telops. Thanks Diego for all the hard work to implement this during the night (which, as you may expect, needs testing with active guiding during the implementation of the feature) and after the network tests.

-Guillermo