5i25 7i85s 7i84 Connection and Configuration

I have been in the process of retrofitting a Prototrak MX3 machine for some time (see this thread as well forum.linuxcnc.org/forum/30-cnc-machines...it-which-boards-mesa )

I now have the 5i25>7i85s combination working well controlling all 3 axes of my machine. With that in place I decided that additional I/O is necessary to address home/limit switches as well as future control of the spindle and coolant etc. Following on the original suggestion of PCW I have purchased and received the 7i84 to handle my additional I/O needs.

After a quick overview, it appears as though I need to connect from the screw terminal serial termination on the 7i85s to the RJ45 termination on the 7i84. If this is correct, I am thinking about using an RJ45 male to Screw Terminal breakout, something like this: www.amazon.com/Parts-Express-RJ45-Screw-Terminals/dp/B00AEBHHLA so that I can use stranded cable rather than trying to utilize CAT6 solid core cable. Is this a sensible solution for this connection?

The next question relates to the Firmware requirements. Will I need to flash new firmware in order to add on the 7i84? Or do I only need to update the config/hal files?

Any input is appreciated.

Easiest way to make the cable is simply cut a CAT6 patch cable in half
and use the color code guide in the 7I84 manual for terminating the 3.5 MM plug

(no firmware needs changing)

So I took the advice of Peter and used the CAT 6 cable and connected everything up. I now believe that I need to update the hal file in order to have the card recognized.

I currently have the following in my hal file which works fine with the 5i25 and 7i84s:

loadrt hm2_pci config=" num_encoders=8 num_pwmgens=8 num_stepgens=0 sserial_port_0=00xxxx"

Do I need to pass a second config string for the 7i84?

It seems as though in another post that I had read, it was suggested that the 7i84 can be set by manipulating the sserial portion of the base config string. i.e.

sserial_port_0=200xxx

Since I am unsure on this, I wanted to reach out to see if I can get a push in the right direction. I do understand that I will need to update the hal file for pin assignments as well but want to take one step at a time and first ensure that the new 7i84 board is recognized correctly.

Thanks,
Jeff

The 7I84 card should be recognized independent of any hal file changes

You can change the sserial_port=something string to set the 7I84s mode

From the 7I84 manual:

SOFTWARE PROCESS DATA MODES
The 7I84 has three software selectable process data modes. These different modes
select different sets of 7I84 data to be transferred between the host and the 7I84 during
real time process data exchanges. For high speed applications, choosing the correct mode
can reduce the data transfer sizes, resulting in higher maximum update rates.

MODE 0 I/O only mode (32 bits of input data, 16 bit of output data)

MODE 1 I/O plus analog input and field voltage mode (32 bits of input data, 16 bits of
output data, 4 analog input channels (on inputs 0..3) and field voltage analog
in)

MODE 2 I/O plus analog input (32 bits of input data, 16 bits of output data, 4 analog
input channels (on inputs 0..3), and 2 MPG encoders on inputs 16..19).
Default encoder count mode is 1X to match normal 100 PPR MPGs.
Encoder input threshold is fixed at 2.5V for compatibility with 5V encoder
outputs.