The drawing you provided shows inputs 1 through 8 could be NPN or PNP in. However, all 8 inputs must be the same.
Inputs 9-16 appear to be seperate from the first block, they could also be either NPN or PNP, but they all must be the same (only one common) (They don't have to be the same as the first block)
Inputs 17 through 24 are all PNP and only PNP.
Inputs 25 through 32 are also PNP
Not quite correct. The top half of the card shows outputs and these are of the NPN output type - note positive common to the load and negative common to the card. The positive into the card is usually only to drive the LED indicators to show which output is on, transistors etc.
The lower half of the card shows inputs of either persuasion. Use a positive common for NPN input or a negative common for PNP input.
Very typical of most Japanese PLCs.
The common for the output section of the card is clearly shown as negative and so the NPN transistor will "sink" low placing a differential voltage across the load (L). This differential will turn the load on but the voltage differential will never be a clean 24VDC but more likely to be about 22VDC.
If the common for the input section of the card is negative, then a PNP output device in the field will switch "high" placing a differential across the input and turning it on. The differential voltage is highly unlikely to be 24VDC from a solid state device in the field but will probably be a volt or 2 lower. A contact closure will show a differential much closer to 24VDC and could be full voltage, mainly depending on voltage drop in field wiring.
This is how I wire all my Omron PLCs - sinking outputs and sourcing inputs. Do not like sinking inputs due to the possibility of a ground causing an input to turn on, although the likelyhood of that is reduced to practically zero if the 24VDC supply is isolated and the negative is
NOT tied to ground - usually use switch mode power supplies that have isolation inherently built in and allow the 24VDC supply to float.
