Problem with amplifier enable

Hello,
every of my servoamplifiers has a 24Volt output. This voltage must be switched to the enable input of the amplifier, for this i will use a relais. Can I switch powersupply5 or 24V > relais > ENAN+ > ENAN- > Ground? Its necessary to switch every amplifier seperate with EN0 - EN2, or can i switch on all three amplifiers with one enable output?

Thanks

Hans

normally you would not use relays but wire

+SERVO24V --> ENA+ --> ENA- --> SERVO-ENABLE (per axis)

Hello PCW,
many thanks for your answer. The relais will be a protection for the 7I77. I will measure the current from 24V to enable.

Thanks

Hans

You may find that the servo enable current is quite a bit lower than the relay coil current
so you are better off driving the servo enables directly from the 7I77

Also, if you drive (small) relays from the ENA outputs you need to have a flyback diode across the relay coil

(and test the relay/flyback diode by hand wiring first, as a backwards flyback diode will damage the
7I77 OPTO isolator ENA driver)

Hello PCW,
thanks for your answer. The amplifiers have normally open contact that closes when the amplifier is ready to work. Can Linuxcnc with 5I25 and 7I77 read this signal and show on the display "amplifier not working" and stop the job?

Hans

yes, normally this get wired to axis.N.amp-fault-in in the hal file

Hello PCW,
I have some pneumatic valves and motor driver relais, some of these parts need more than 500mA. Can I switch them and the amplifier enable with solid state relais? I mean they do not have a back electromagnetic impuls?

Thanks

Hans

Yes, you can use a solid state relay to control them.