Joe's 1000x600x200 steel and aluminium router started

[devmonkey]

How do people usually wire the alarm outputs of the drivers?

My plan was to place these in series with the estop but this wont actually work for me. Reason being estop unlatches the relay that switches the main contactor that switches AC into the driver PSU, this means that the drivers are unpowered until reset is pressed latching the relay, however the relay wont latch as the drivers are unpowered therefore cannot switch on their open collector alarm outputs breaking the estop circuit.

The only thing I can think of is to add another relay in series with estop, via the normally closed contact and then have the driver alarms open this relay, this has the downside that you don't know if the alarm circuit is intact until it doesn't work.

[Neale]

How do people usually wire the alarm outputs of the drivers?

My plan was to place these in series with the estop but this wont actually work for me. Reason being estop unlatches the relay that switches the main contactor that switches AC into the driver PSU, this means that the drivers are unpowered until reset is pressed latching the relay, however the relay wont latch as the drivers are unpowered therefore cannot switch on their open collector alarm outputs breaking the estop circuit.

The only thing I can think of is to add another relay in series with estop, via the normally closed contact and then have the driver alarms open this relay, this has the downside that you don't know if the alarm circuit is intact until it doesn't work.

I have wired fault outputs in series and taken that to a "servo fault" input on the motion controller. Partly for the reason you give - can't put power on the drivers via the safety relay until there is power on the drivers - and partly because I classify "fault" signals into two categories. Personal safety - when you hit estop you really want it to stop NOW so that is a safety relay task (mine cuts driver power, driver enable, and signals motion controller), and machine issue - driver fault, limit switch - and I'm happy that motion controller firmware can be trusted for that. Does DDSC have "driver/servo fault" input(s)?