Spindle encoder help

Hi, I'm having trouble with the lathe spindle encoder reading freezing above 180rpm.

Im using a 90 slot disc and a sensor www.ebay.co.uk/itm/2-Channel-2CH-Speed-D...?hash=item41cd81e203

This is then feed into a bob www.ebay.co.uk/itm/5-Axes-CNC-Breakout-B...?hash=item2cc5392542

I have set everything up as per the guides but any thing over 180 rpm and the reading freezes. I've checked the hal meter for the pins and getting 90 counts for 1 revolution

Could it be the cheap bob? or will the pp not accept a 90 ppr encoder?

Unfortunately the machine is in the workshop and I forgot to copy the files to post up. i can get them tomorrow if needed.

Thanks in advance

Those cheep bobs often have rather crappy optos that are quite slow. (I'd be surprised if they are that slow though.)
But it would not be hard and probably worth the effort to rig up a test to see if results are any better without the bob in the way.

All solved. Turned out to be the trim pot on the 2 channel sensor board. I have no idea why that would affect it but i changed the setting and i started working at the higher rpm.

Thanks anyway, sorry