Hi @nitrousdude
A search online for a ''BCI 4 Channel/Distance Analog Output Cable (Polysomnography) for Capnocheck Sleep'' came up with these [https://www.google.com/search?client=firefox-b-d&q=BCI+4+Channel%2FDistance+Analog+Output+Cable+%28Polysomnography%29+for+Capnocheck+Sleep|suppliers]
Interesting to note that some suppliers link the cable as being suitable for both the Plus and Sleep models
If this is the case, I think that perhaps as far as the analogue output pin connections are concerned that they should be the same.
Here's the [document|18286].
On p.20 of 66 it states that the analogue output is fed to a DB25 connector.
On p.57 of 66 the schematic shows the DB25 connector pinout wiring. I assume that this is the correct one, because it is the only DB25 connector shown in all the schematics