Kelvin,

I am certain that there is not any standards on Mag-Reader pinouts.
Your example of the Omron 3S4YR-HNR-4U used 9 pins.
I am holding in my hands, Omron 3S4YR-HSR4, it uses a 5 pin connect.
In the other hand is Omron 3S4YR-SRB4-20 Insert reader, it uses a 10 pin.
I also have a Magtek 21050055 on my bench, it uses a 6 pin (but with only
5 wires runing to it). I have seen probably a dozen (or more?) mag readers.
They do not have a standard wiring. Please refer to my first response to see how I would go about figuring the pinout.

Josh.