What is M code in mitsubishi qd75d4?

[christophertedjo]

i have a question about M codes. what is it?

using QD75D4 motion control

[drforsythe]

M Code is a standard instruction set for CNC machines.

[Crossbow]

dforsythe, you are thinking of G code.

M code is a numeric code which is stored when the control reaches that step in the program.  For example it can be a step number.  It's use is optional, so it's really up to you how/if you use it.

[drforsythe]

Crossbow, that is not the way I understand it.  I was taught that G codes typically deal with the motion control aspect of a CNC and M codes deal with the canned functions like turning the coolant on and off or turning a spindle on and off.  I am not a CNC expert, but the motion controllers I have used operated this way.  A quick Google search confirmed this.  Maybe it is device specific?

[Crossbow]

M code is entirely up to the end user.  It's just a number written to a register.  Sometimes it's written at the start of a motion step and sometimes at the end.