MASSO Documentation

MASSO G3 Replacing Damaged Optocouplers




Identifying Optocouplers

  • Inputs - Opto 1 to 8, 10 to 24: LTV-816 or KB817
  • THC Input - Opto 9: SFH615A-2
  • Spindle Encoder Inputs - Opto 25, 26 & 27: SFH615A-2
  • MPG Inputs - Opto 28 to 38: LTV-816 or KB817
  • Spindle CW & CCW Outputs - Opto 39 & 40: LTV-816 or KB817

Sourcing replacement parts


INFORMATION: Damaged Optocouplers can be purchased from one of the following suppliers, please click the link below to directly jump to the part order page:



Digi-Key: Optocoupler LTV-816


Newark Element 14: Optocoupler KB817


Mouser Electronics: Optocoupler LTV-816





Testing procedure for Inputs 1 - 24



Testing procedure for Spindle Encoder Inputs



Testing procedure for MPG Inputs


Testing procedure for the Estop Input



Testing procedure for CW & CCW outputs


Replacement Process

WARNING: Ensure that you turn the power off to MASSO and observe standard Antistatic precautions before changing an optocoupler.


CAUTION: Ensure that you observe the correct orientation of the optocoupler when replacing as they are polarity sensitive.