Smart Serial port not detecting remote 7i87 card

I'm stumped. I have a mesa 6i25 pci card with firmware configured for five stepgens and one SSerial channel. I am trying to connect a mesa 7i87 ADC card on the serial port but I get no indication that the 7i87 card is detected.

I have checked the wiring several times. The board is getting power. When I start linuxcnc and bring up 'hal configuration' I expected to see some reference to the 7i87 - but nothing there. Is there some way to debug this systematically?

> 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)

In HAL file:

loadrt hostmot2
loadrt hm2_pci config=" num_encoders=0 num_pwmgens=0 num_stepgens=5 sserial_port_0=0xxxxx"

What am I missing?


 

What daughtercard do you use?
Maybe an interface/pinout/polarity issue

Its supposed to be:

hm2_5i25 < sslbp > 7i87

You need a RS-422 interface with the correct pinout and polarity
between the 5I25 and 7I87. That's why I asked about the
daughtercard you are using.

Ok, I should have been more detailed. The connections are:

hm2_5i25 < sslbp > < TTL-RS485 > 7i87

I'm using the TTL to RS485 translator the MESA told me to use. It and the 7i87 card have power but I don't know if the signal is getting through.

My guess is that its a wiring error of some kind
can you show the connections between the 5I25 RX and TX
signals, the RS485.422 transceiver, and  the RJ-45 pins?

 [attachment=61888]TTL-RS485-wiring.png

I have to go now. I will check in later.

Unfortunately your schematic did not get attached properly.

Sorry, about the bad attachment. I'll try again but I think I found a problem with the differential pairs having the polarity reversed. I can't test it now but will swap the wires as soon as I get time.