Smart Serial port not detecting remote 7i87 card

vedatech wrote:

What triggers the smart serial channel to probe any attached cards?
Does it happen on power up? When linuxcnc starts?
 

Yes, it happens when the hm2_xxx driver is loaded.

Yes, I was confused about the wiring. It is fixed now with TX > RX, RX > TX but I still not detecting the 7i87 and I'm not even certain that the sserial port is working even though mesaflash shows the module is loaded:

> sudo mesaflash --device 5i25 --readhmid
IO Connections for P3
DB25 pin# I/O Pri. func Sec. func Chan Sec. Pin func Sec. Pin Dir

1 0 IOPort PWM 0 PWM (Out)
14 1 IOPort None
2 2 IOPort StepGen 0 Step/Table1 (Out)
15 3 IOPort None
3 4 IOPort StepGen 0 Dir/Table2 (Out)
16 5 IOPort StepGen 4 Step/Table1 (Out)
4 6 IOPort StepGen 1 Step/Table1 (Out)
17 7 IOPort StepGen 4 Dir/Table2 (Out)
5 8 IOPort StepGen 1 Dir/Table2 (Out)
6 9 IOPort StepGen 2 Step/Table1 (Out)
7 10 IOPort StepGen 2 Dir/Table2 (Out)
8 11 IOPort StepGen 3 Step/Table1 (Out)
9 12 IOPort StepGen 3 Dir/Table2 (Out)
10 13 IOPort StepGen 5 Step/Table1 (Out)
11 14 IOPort StepGen 5 Dir/Table2 (Out)
12 15 IOPort SSerial 0 TXData0 (Out)
13 16 IOPort SSerial 0 RXData0 (In)

However, hal configuartion only shows the StepGen pins and everything else is just IOPort. How can I check to set if SSerial is actually working?

I have to get some sleep but I'll check again in the morning

All's well that ends well. The 7i87 card is now detected and its pins and parameters are visible in hal configuration.
Just a series of stupid wiring mistakes and wrong assumptions on my part. The final thing that got it working as realizing that TXEN doesn't mean TX Enable it means TX Enable NOT. Once I grounded it I saw nice clean differential pulses on the output of the TTL-RS485 converter.
Now I can work on the software.
Thanks for your help PCW.

One new issue though. The 7i87 works fine in mode 0 but linuxcnc fails if I set it to mode 1 or 2. I only want to use mode 0 but any idea why this happens?

Not sure, what does your config line look like?

Yes there's a bug of some kind with the 7I87 and modes >1 with recent
LinuxCNC versions. I will take a look at this later this week.