Help me use two 7i96s in Ethernet switch to control 6 joints

 Hello. Recently I’ve had problems controlling XYZAB because in fact I have two YY motors, so I need 6 Stepgens to avoid some issues I was having.  I added a 7i96s card and a switch, and added 10.10.10.11 and 10.10.10.12 in the Ethernet connections, also with gate 8. I’m not sure how to proceed with the ini/hal changes, tried some ideas around adding a second card IP, card1 read and write, and others, but no matter how, I couldn’t power up the system with both cards. Is there a base config o could work with to have both cards working? Any tips in having both cards working? I can ping both IPs, but I’m not sure if i won’t have other connectivity issues. Thank you in advance.

You need two network cards for that, no switch.

I know you already have two 7i96 cards, but perhaps using only one of them with a 7i78 daughter card connected to the expansion port of the 7i96 might be a better option than the two 7i96 cards to get extra stepgen outputs?

Did you change the IP address on one of the 7i96 cards so that they are not the same? Set the first as 10.10.10.10 and the second as 10.10.10.11. You have to use the Mesa flash utility to set the address on the card. Set the static IP for the nic on your Linuxcnc PC to 10.10.10.100 (or something other than 10.10.10.10 or 10.10.10.11 but in the same range.)

I believe you can use a switch, but the switch and the PCs ethernet port need to be dedicated only to this use. If you want to also have an ethernet network/internet connection you will need a second nic on the pc for that.

Here's a thread with instructions from Peter at Mesa
www.forum.linuxcnc.org/38-general-linuxc...sa-7i92-via-ethernet

Todd Zuercher wrote:

I believe you can use a switch, but the switch and the PCs ethernet port need to be dedicated only to this use. If you want to also have an ethernet network/internet connection you will need a second nic on the pc for that.

 

I have not tried that recently, but it has worked for me in the past. I had two Mesa cards connected to a switch, each with its own address.

When I tried connecting other devices to that switch, (modbus tcp, etc), that did not work. Those needed an additional NIC.

Some switches do not behave. I tried using a router instead of a switch one time, that did not work either.

You could try an audio switch, or other high performance switch. I think though that the network card suggestion is the better route. Alternately, is there no breakout board to add something like a 7i78 to the 25pin expansion?

Easiest way would be to add a breakout board like a 7I78, 7I85S, or the common Chinese (Sainsmart)
parallel port breakout. There is 7I96S firmware for all of these breakout boards.

You can use a switch to run up to 4 Mesa Ethernet cards at once, This is better with  hal changes so that
the read times are overlapped instead of added.

Normal hal addf layout would be something like:

addf read0
addr read1
[ bunch of processing addfs]
addf write0
addf write1

But this means that the second read needs to wait for the first to complete before
starting, so to overlap the reads, you:

addf read-request0
addf read-request1
addf read0
addr read1
[ bunch of processing addfs]
addf write0
addf write1