This morning, after a model restart, the ISS second loop configuration was no more correct. We should save a reference snapshot at some point. For the moment, here is a picture of the "standard working configuration" at the moment.

This configuration ensures that the switches and gain sliders of the second loop are working properly. For some reason, the model sums the analog SUM signal to the digital SUM signal. To avoid this, the filter banks PD_14_SUM and PD_58_SUM shuold have the output turned off.

Since only the SUMXX_REL_OUT is saved to disk, for the moment being I hacked the configuration of  SECONDLOOP_SUMXX_DC to provide a constant offset equal to the total DC in the PD sum, in volts. Therefore the _REL signals are now calibrated in units of dP/P and saved to disk.