Mesa 7i77 confirm estop

Hi,
I am working with a Mesa 7i77.
For safety reasons I operate the mesa with a separate Field Power and logic Power (Jumper W1 is placed in the right-hand position)
If I cut off the Field Power with the emergency stop, all Outputs are low and I got the Error Message:that’s all fine!
If I reconnect the Field Power, I can control the Outputs with linuxcnc (Outputs are set in the HALSHOW)
But the Outputs are not controlled at the Mesa board.

Is there any possibility to reset the Mesa board (without closing LinuxCNC)?

Best regards,
Thom

You should not switch the DC 7I77 field power. If you have a specific safety related output
you should instead include it in the estop chain. If you must switch 7I77 field power
it should be done on the primary (AC) side of the field power source.

You can recover from loss of sserial communication by setting the "run" pin false and then true

Thank you very much, PCW!

You can recover from loss of sserial communication by setting the "run" pin false and then true

It works!

If you must switch 7I77 field power it should be done on the primary (AC) side of the field power source.

Ok, I thought you can use the FIELD POWER like the 1L on a Siemens SPS...?
There I learned to cut off the 24V control Voltage (for actors) with the emergency relay
All the other 24V are still in use (e.g. for sensor inputs, supply for the control, status lights, …)

Best Regards,
Thom

There are 2 reasons you cannot switch the DC field power on a 7I77:

1. Field power supplies electronic devices with filter capacitors and switching the
DC side can cause DVDT/DIDT failures
2. The field voltage sets the input thresholds

You can switch the load power with a 7I77D (since you use 12/24V common for all loads)
And we have firmware that uses host settable thresholds so allows dropping the field voltage without error, but this is not released for the 7I77 yet (it is available for the 7I84)

ok, that make sense. Thanks

2. The field voltage sets the input thresholds

just recognized that

Thom wrote:

ok, that make sense. Thanks

2. The field voltage sets the input thresholds

just recognized that

Cut the power on the output of the field power. Don't cut power feeding field power.

Use a different terminal for emerg safety switch and cut power there, so your removed the input basically.