Updated drawing of Gecko G540 Estop slaved from a Masso Estop.
Flyback (Protection) diode has been removed from original as the Masso has internal Flyback diodes.
EDIT.... EDIT.....
If you like reading the 3 or 4 pages of text in this thread to see how this story pans out, do so by all means. But if you want to cut to the chase quickly, here is the end result of this fairly long back and forth discussion.
Masso made at least one hardware change to the Masso controller starting with Revision 6 of the Masso PC board. See image below to find out where to check Revision number.
While this revision does not affect the operation of your Mass0 in any way it does change the required external wiring if you are using a relay connected to Relay 7 (the Estop relay) of the Masso to call an Estop on another piece of equipment, in my case a Gecko G540 stepper driver.
- With board revisions 1 through 5 inclusive, an Estop operation will operate a relay connected to Relay 7 connector.
- With board revisions from 6 onwards, an Estop operation will release a relay connected to Relay 7 connector (In other words Relay 7 would operate during normal Masso operation).
How this affects your relay wiring is diagrammed in the attached image. The reason for this change is that in normal operation the relay is energised - but on a fault condition for whatever reason with the relay circuitry the relay will drop-out causing an Estop. Very logical, thanks Masso.