LinuxCNC compatible VFD's

Hi,

How do I go about finding LinuxCNC compatible VFD's when having to replace my current?
Looking for a 7.5 kW drive with serial communications support.

In the linuxcnc manual , under Hardware Drivers, you will find the standard drivers. But with mb2hal, VFDMOD, Classic Ladder, etc.. you can communicate with every VFD that uses standard modbus.

Just to insert a mention of mesa_modbus, which should allow realtime Modbus control via the Mesa card UARTs.

The manpage for this also lists the dedicated drivers and other modbus tools:

linuxcnc.org/docs/stable/html/drivers/mesa_modbus.html

I didn't think it was possible to use the serial connection on the MESA board for modbus; quite sure I've seen comments about it seaching the forum. New features enabled by PCW?

To be spesific; can I use the RS-422 serial port on the MESA 7i77 for modbus communication with a VFD supporting RS-485 modbus? No need for USB dongle?

I added this to my shopping basket yesterday in frustration over the old one;
no.mouser.com/ProductDetail/Delta-Electr...=NO¤cyCode=NOK

tom_no wrote:

To be spesific; can I use the RS-422 serial port on the MESA 7i77 for modbus communication with a VFD supporting RS-485 modbus? No need for USB dongle?

Probably not, but PCW would know for sure. It depends if that RS422 port has a tx-enable pin. Only one of those on the 7i74 is available because of this limitation, and the 7i77 is also a 25-pin card, so probably runs into the same pin-count limitation. 

To go into this further, the 7i74 pinout on page  4 here  has a single /TXEN7 pin. The 7i44  has one for every channel. 
Looking at the manual for the 7i77   it looks like SmartSerial Channel2 does have TXEN pin, so there is a fair chance that it can be made to work, if SS2 is the expansion channel. 
It would need a custom firmware with a UART on that channel instead of a smart-serial module.