Mesa 7i96s + VFD MODBUS HELP!

Hi all,
I just migrated from Mach3 to LinuxCNC. I am just a beginner in LinuxCNC.
I'm trying to use rs485 port on my mesa card to talk to my vfd/spindle.

I am following instructions from here:
linuxcnc.org/docs/2.9/html/drivers/mesa_modbus.html

i compiled the generic example mod file provided and try lo load it through my config.
I get an error: hm2: Cannot find PkgUART instance on hm2_7i96s.0.pktuart.0

How can i enable/install PkgUART? Do i need a custom firmware for my card?

You would need to use 7I96S firmware that includes a PacketUART module,

7i96sd_pktv2.bin

Would be the suggested one

Also wanted to add this excellent video by talla83 explaining how to customize and compile the bin file. He adds new modules and make it available on the expansion port to use with jumper wires. Neat..

First i managed to control to my spindle, but then it stopped working.

Things i have tried:
I checked cables and vfd, using another usb-rs485 converter, they have no problem

I tried hooking up a logic analyzer to the TX port, TB2 pins 18 and 19 on my 7i96s.
i am writing to coils and registers to the test pins i created but there seems to be no life on my port.

i reflashed the mesa card

mydevice.00.fault pin goes true as soon as i run the configuration and mydevice.00.last-error pin shows 11 (timeout)
But that was the situation with those pins before and i was able to control my spindle without problems.

Is there a way i can troubleshoot this?
I am afraid if i had toasted the port by connecting wrong terminals

Can you try this script:

 

With the cabling that connects RX+ to TX+ and RX- to TX- (RS-485 connection)
with the proper bias resistors and report the results here
 

I took the card to home, so i cannot test on vfd, but somehow i guess i shall see some data on my logic analyzer. I'm no electronics expert but in the past i used it to troubleshoot some obscure modbus devices to make them work with Arduino.

it prints these in terminal some user leds turn on some turn off

and the red light on my logic analyzer turns on (the codes absolutely make a difference)

If i go halrun and enter my config line by line
when i enter this line:

red light on the logic analyzer turns off

when i enter "start" command, screen fills with this (I think i enabled debug mode, that may be the reason)

and also if i run the gui instead of halrun, i get this error:

I still have zero action on the logic analyzer

i will have a look at the bias resistors and report again.

0000C3FF 000003FF 000043FF

Means that the TX data is not echoed
on the RX data pin which does suggest
that the SP491 RS422/485 driver chip
is damaged (or there is a connection
issue since this test depends on the
TX --> RX loopback)

I would expect 06XXX at the end if the
RX pin followed the TX

0x8000 is the TXEN bit (active low)
0X4000 is the TX bit
0x2000 is the RX bit

Basically what the test does is clear
the I/O setup registers then enable
GPIO outputs on TX and TXen
(both will be low at first and low TXen means
enabled) then sets TX data high (0x4000)
to see if its echoed on RX (0x2000)

the vfd i use has A and B connections only and i was using only Tx pins on the mesa card, since i was only sending frequency and turn spindle values.

As i understand from your message rx pins must be connected as well for the test to be successful

can you suggest a proper wiring diagram with resistors.
I know i am asking for much but it should be useful for other users as well

7I96 TB2
15 GND  --> 330 Ohm --> RX+ 
16 RX+  --> TX+
17 RX-   -->  TX-
18 TX+
19 TX-
20 5V  --> 330 Ohm --> RX-

with the wiring you provided test commands print as follows: