Recently we got 2x P4305 mainly because they are easy to automate using their serial interface. I found a "ODP Series DC Power Supply Programming Manual" on the CD that came with it. There are no manuals for this product, but manuals for similar OWON products.
Fan has temperature control, toroidal mains transformer. Wideband output noise is about 40 mVpp.
The incomplete overvoltage/overcurrent implementation mentioned above can be completed on the host side. I mean the host can clip the set voltage and current to be inside the limits before setting them.
Appended linearity tests are sweeps of measured output voltage deviation from set voltage, 0.1 V steps every 2 seconds. With and without load the average deviation is about -1 mV, for both units out of the box.
Comparison with a Keithley 2700 gave good results, too. I mean the built-in meters of the power supplies are well calibrated and agree to their last digit, e.g. 4,998 V was 4,99797 V on the K2700 with about +/- 20 uV short term stability. On the other unit 30.000 or 29.999 V was displayed and gave 30.0003 V on the K2700.
Best regards, Dieter