Best/easiest way to hook up a 7i73 to a PC?

Ahh that does look like a driver bug with defaults.
Should be fixable by including all ports in the config
string (which is likely needed anyway to set the modes)

I will take a look
(the driver should really treat all ports the same anyway)

Looks ok with master:

halcmd: loadrt hostmot2
Note: Using POSIX realtime
hm2: loading Mesa HostMot2 driver version 0.15
halcmd: loadrt hm2_eth board_ip=10.10.10.10
hm2_eth: loading Mesa AnyIO HostMot2 ethernet driver version 0.2
hm2_eth: 10.10.10.10: INFO: Hardware address (MAC): 00:60:1b:16:00:02
hm2_eth: discovered 7I96
hm2/hm2_7i96.0: Low Level init 0.15
hm2/hm2_7i96.0: Smart Serial Firmware Version 43
Board hm2_7i96.0.7i87.0.0 Hardware Mode 0 = standard
Board hm2_7i96.0.7i87.0.0 Software Mode 0 = analoginput_digitaloutput
Board hm2_7i96.0.7i87.0.0 Software Mode 1 = analoginput16bit*4,8bit*4_digitaloutput
Board hm2_7i96.0.7i87.0.0 Software Mode 2 = analoginput16bit*6_digitaloutput
hm2/hm2_7i96.0: Smart Serial Firmware Version 43
Board hm2_7i96.0.7i73.1.0 Hardware Mode 0 = nokeyboardnodisplay
Board hm2_7i96.0.7i73.1.0 Software Mode 0 = inputoutputencoder
Board hm2_7i96.0.7i73.1.0 Software Mode 1 = inputoutputencoderanalog
Board hm2_7i96.0.7i73.1.0 Software Mode 2 = inputoutputencoderanalog
Board hm2_7i96.0.7i73.1.0 Hardware Mode 1 = nokeyboarddisplay
Board hm2_7i96.0.7i73.1.0 Software Mode 0 = inputoutputencoderdisplay
Board hm2_7i96.0.7i73.1.0 Software Mode 1 = inputoutputencoderanalogdisplay
Board hm2_7i96.0.7i73.1.0 Software Mode 2 = inputoutputencoderanalogwidedisplay
Board hm2_7i96.0.7i73.1.0 Hardware Mode 2 = keyboard4by8nodisplay
Board hm2_7i96.0.7i73.1.0 Software Mode 0 = inputoutputencoderkeycode4by8
Board hm2_7i96.0.7i73.1.0 Software Mode 1 = inputoutputencoderanalogkeycode4by8
Board hm2_7i96.0.7i73.1.0 Software Mode 2 = inputoutputencoderanalogkeycode4by8
Board hm2_7i96.0.7i73.1.0 Hardware Mode 3 = keyboard4by8display
Board hm2_7i96.0.7i73.1.0 Software Mode 0 = inputoutputencoderdisplaykeycode4by8
Board hm2_7i96.0.7i73.1.0 Software Mode 1 = inputoutputencoderanalogdisplaykeycode4by8
Board hm2_7i96.0.7i73.1.0 Software Mode 2 = inputoutputencoderanalogwidedisplaykeycode4by8
Board hm2_7i96.0.7i73.1.0 Hardware Mode 4 = keyboard8by8nodisplay
Board hm2_7i96.0.7i73.1.0 Software Mode 0 = inputoutputencoderkeycode8by8
Board hm2_7i96.0.7i73.1.0 Software Mode 1 = inputoutputencoderanalogkeycode8by8
Board hm2_7i96.0.7i73.1.0 Software Mode 2 = inputoutputencoderanalogkeycode8by8
Board hm2_7i96.0.7i73.1.0 Hardware Mode 5 = keyboard8by8display
Board hm2_7i96.0.7i73.1.0 Software Mode 0 = inputoutputencoderdisplaykeycode8by8
Board hm2_7i96.0.7i73.1.0 Software Mode 1 = inputoutputencoderanalogdisplaykeycode8by8
Board hm2_7i96.0.7i73.1.0 Software Mode 2 = inputoutputencoderanalogwidedisplaykeycode8by8
hm2/hm2_7i96.0: 51 I/O Pins used:
hm2/hm2_7i96.0:     IO Pin 000 (TB3-01): IOPort
hm2/hm2_7i96.0:     IO Pin 001 (TB3-02): IOPort
hm2/hm2_7i96.0:     IO Pin 002 (TB3-03): IOPort
hm2/hm2_7i96.0:     IO Pin 003 (TB3-04): IOPort
hm2/hm2_7i96.0:     IO Pin 004 (TB3-05): IOPort
hm2/hm2_7i96.0:     IO Pin 005 (TB3-06): IOPort
hm2/hm2_7i96.0:     IO Pin 006 (TB3-07): IOPort
hm2/hm2_7i96.0:     IO Pin 007 (TB3-08): IOPort
hm2/hm2_7i96.0:     IO Pin 008 (TB3-09): IOPort
hm2/hm2_7i96.0:     IO Pin 009 (TB3-10): IOPort
hm2/hm2_7i96.0:     IO Pin 010 (TB3-11): IOPort
hm2/hm2_7i96.0:     IO Pin 011 (TB3-13/TB3-14): SSR #0, pin Out-00 (Output)
hm2/hm2_7i96.0:     IO Pin 012 (TB3-15/TB3-16): SSR #0, pin Out-01 (Output)
hm2/hm2_7i96.0:     IO Pin 013 (TB3-17/TB3-18): SSR #0, pin Out-02 (Output)
hm2/hm2_7i96.0:     IO Pin 014 (TB3-19/TB3-20): SSR #0, pin Out-03 (Output)
hm2/hm2_7i96.0:     IO Pin 015 (TB3-21/TB3-22): SSR #0, pin Out-04 (Output)
hm2/hm2_7i96.0:     IO Pin 016 (TB3-23/TB3-24): SSR #0, pin Out-05 (Output)
hm2/hm2_7i96.0:     IO Pin 017 (TB1-02/TB1-03): StepGen #0, pin Step (Output)
hm2/hm2_7i96.0:     IO Pin 018 (TB1-04/TB1-05): StepGen #0, pin Direction (Output)
hm2/hm2_7i96.0:     IO Pin 019 (TB1-08/TB1-09): StepGen #1, pin Step (Output)
hm2/hm2_7i96.0:     IO Pin 020 (TB1-10/TB1-11): StepGen #1, pin Direction (Output)
hm2/hm2_7i96.0:     IO Pin 021 (TB1-14/TB1-15): StepGen #2, pin Step (Output)
hm2/hm2_7i96.0:     IO Pin 022 (TB1-16/TB1-17): StepGen #2, pin Direction (Output)
hm2/hm2_7i96.0:     IO Pin 023 (TB1-20/TB1-21): StepGen #3, pin Step (Output)
hm2/hm2_7i96.0:     IO Pin 024 (TB1-22-TB1-23): StepGen #3, pin Direction (Output)
hm2/hm2_7i96.0:     IO Pin 025 (TB2-02/TB2-03): StepGen #4, pin Step (Output)
hm2/hm2_7i96.0:     IO Pin 026 (TB2-04/TB2-05): StepGen #4, pin Direction (Output)
hm2/hm2_7i96.0:     IO Pin 027 (TB2-07/TB2-08): Encoder #0, pin A (Input)
hm2/hm2_7i96.0:     IO Pin 028 (TB2-10/TB2-11): Encoder #0, pin B (Input)
hm2/hm2_7i96.0:     IO Pin 029 (TB2-13/TB2-14): Encoder #0, pin Index (Input)
hm2/hm2_7i96.0:     IO Pin 030 (TB2-16/TB2-17): Smart Serial Interface #0, pin rx0 (Input)
hm2/hm2_7i96.0:     IO Pin 031 (TB2-18/TB2-19): Smart Serial Interface #0, pin tx0 (Output)
hm2/hm2_7i96.0:     IO Pin 032 (internal): Smart Serial Interface #0, pin txen0 (Output)
hm2/hm2_7i96.0:     IO Pin 033 (internal): SSR #0, pin AC Ref (internal) (Output)
hm2/hm2_7i96.0:     IO Pin 034 (P1-01/DB25-01): Smart Serial Interface #1, pin rx0 (Input)
hm2/hm2_7i96.0:     IO Pin 035 (P1-02/DB25-14): IOPort
hm2/hm2_7i96.0:     IO Pin 036 (P1-03/DB25-02): IOPort
hm2/hm2_7i96.0:     IO Pin 037 (P1-04/DB25-15): IOPort
hm2/hm2_7i96.0:     IO Pin 038 (P1-05/DB25-03): Smart Serial Interface #1, pin tx0 (Output)
hm2/hm2_7i96.0:     IO Pin 039 (P1-06/DB25-16): IOPort
hm2/hm2_7i96.0:     IO Pin 040 (P1-07/DB25-04): IOPort
hm2/hm2_7i96.0:     IO Pin 041 (P1-08/DB25-17): IOPort
hm2/hm2_7i96.0:     IO Pin 042 (P1-09/DB25-05): IOPort
hm2/hm2_7i96.0:     IO Pin 043 (P1-11/DB25-06): IOPort
hm2/hm2_7i96.0:     IO Pin 044 (P1-13/DB25-07): IOPort
hm2/hm2_7i96.0:     IO Pin 045 (P1-15/DB25-08): IOPort
hm2/hm2_7i96.0:     IO Pin 046 (P1-17/DB25-09): IOPort
hm2/hm2_7i96.0:     IO Pin 047 (P1-19/DB25-10): IOPort
hm2/hm2_7i96.0:     IO Pin 048 (P1-21/DB25-11): IOPort
hm2/hm2_7i96.0:     IO Pin 049 (P1-23/DB25-12): IOPort
hm2/hm2_7i96.0:     IO Pin 050 (P1-25/DB25-13): IOPort
hm2/hm2_7i96.0: registered

halcmd:


 

I'm not sure what you're testing there. Please re-read the bug description.

The bug is still present in current master.

To reiterate: the bug is that with the 5i25_7i77_7i74 firmware and the hm2_pci driver, the "sserial_port_0=00000000" statement forces all of the port 1 IO pins to switch to their Smart Serial Interface function, despite them not having been configured as such and regardless of there being anything connected to them or not.

Edit: Correction: the port 1 pins are displayed as Smart Serial Interface ports on linuxcnc startup, but they still won't function as such - e.g. my 7i73 is not detected in this state. Which can be quite confusing.
 

OK this is unrelated to the firmware or hm2_pci and just
seems to be in the drivers debug printout

Edit:

Looking into this a little further shows that the default (no port 1 modes specified)
setup of port1 is wrong  but every thing works as expected if you specify the modes for port1

Yes, I can confirm that things seem to work as expected with an sserial_port_1 spec included the config.