I have been running my machine several years, including yesterday.  Now I get the emergancy mode active, external estop requested.  I have changed the backup file to several days ago, to no effect. 
Help please
Jay

First step would be to thoroughly check your inputs wiring and EStop / Home / Limit switches.

Tweakie.

I have tried each one by disconnecting the wire one by one, and will try again by disconnecting them all.
Jay

Hi Jay,

Home / limit switches are generally 'normally closed contact' and wired in series - perhaps yours are wired differently ?
Sometimes mechanical switches go bad and tapping them gently with a screwdriver handle can reveal a problem.

Tweakie.

With all input pins disconnected, no change.  Still get emergancy mode and external estop requested.  What is a external estop?
Jay

Hi Jay,

Are your switches wired as 'normally closed contact' ?

If your switches are 'normally closed contact' and wired in series then disconnecting them is of no help - they must be connected and producing a closed circuit.

Use a multimeter and check your Estop switch ...
Is it closed circuit ?
Press the switch - is it open circuit ?
Release the switch is it closed circuit again ?

Check your other switches the same way.

Tweakie.

Thank you,  one of the limit switches got nocked out of adjustment and was open when it should have been closed.
Thanks again
Jay