7i77 -> Huanyang

Scratching my head a bit on the wiring here, I'm probably just nuking it. As far as I can tell the pins from the analog servo control would be
TB5 GND to ACM
TB5 ANALOG OUT to VI

But what I am unsure about is how to do the Forward and reverse. The FOR and REV pins are sourced against the DCM pin on the drive for either direction. My only thought is to use either one or two output pins from T7 or T8 to a relay. Any other option?

The analog will be negative to reverse. This is the output will be between -10 to 10, being 0volts velocity=0.

Edit: I was thinking about a servo drive only, although it can also be applied to a VFD if your VFD can work with -10 to 10. It is also possible to use one output from the 7i77 that will be high if the rotation is FWR or low if it is REV, then connect that output to your VFD. The analog from the mesa card must be then a abs() so that its value is always positive.

unfortunately the Huanyang VFD

doesn't work like that as far as I can tell from the manual.

0~+10V corresponding to the
highest operating frequency

in other words it will not take a Negative Voltage for reverse

I can use the analog voltage to start/stop and set the speed of the motor but not set the direction. that is what the FOR and REV pins are for.

I'm not sure how that high or low output would work with the VFD without adding some sort of circuit to translate.

attached is the manual for some Chinese clarification.

Yeah unfortunately you need to have sinking outputs for the Huanyang
and only the enable output is available on the 7I77

A single SPDT relay can be used this way:

7I77 ENA5- to GND
7I77 ENA5+ to relay common
relay NC to FOR
relay NO to REV
relay coil to 7I77 output (DIR)

other options are transistors or perhaps optoisolators

kinda what I was thinking, thanks for the confirmation

PCW wrote: Yeah unfortunately you need to have sinking outputs for the Huanyang
and only the enable output is available on the 7I77
...
other options are transistors or perhaps optoisolators

Would a ULN2003 work?