Are multiple iterations of the same MESA hardware allowed?

I have a deduced answer given that the pins for the these things are named blahblah.0.gpio.NNN. I'm assuming that .0. is there because there could be one or more iterations of the same device.

The only real downside to the 7i92 I have run into so far is that there is less I/O than most of the other cards. In designing in a physical control panel I am pretty sparse on available I/O for buttons and lights. A PoKeys55 would be one solution to allowing a good deal more I/O but that has really puny current limits and by the time I buy the motherboard that boosts that a bit I'm into about the same price as another 7i92. Thought was that it could live in the control panel itself and that adds 34 I/O. Plenty for a few dials, lights, and buttons to supplement my pendant.

Am I correct in my deduction that I can run two hm2_eth drivers for a 7i92?

Yes, you can use as many as you can connect (or at least .

But, there might be a neater way. Rather than a pokeys take a look at the Mesa 7i73

Are you using the 7i92 with a break-out board or just as-is?
(Actually, a 7i76 connected to the 7i92 would solve the problem too, but then you might as well have started with the 7i76E)

Actually the Ethernet driver is limited to 4 cards (you only run one driver)
Also to get a reliable 1 KHz update rate with 4 cards you need a fast CPU

If you dont need a DB25 pinout you could use a 7I93 instead
( 48 I/0 ) or just use a 7I80DB (a 7I80DB-16 is cheaper than 2 7I92s and has twice the I/O)
Or as Andy suggested, just use a 7I76E

andypugh wrote: Yes, you can use as many as you can connect (or at least .

But, there might be a neater way. Rather than a pokeys take a look at the Mesa 7i73

Are you using the 7i92 with a break-out board or just as-is?
(Actually, a 7i76 connected to the 7i92 would solve the problem too, but then you might as well have started with the 7i76E)

I'm using the 7i92 as is. The DB25 output of P2 goes (or will go) to an MX4660. The P1 header is populated with a DB-25 to ribbon cable adapter and that brought up to a DB-25 breakout to distribute the signals.

The 7i73 sounds interesting assuming I can determine how to get the RS-422 serial connection it uses.

photomankc wrote: The 7i73 sounds interesting assuming I can determine how to get the RS-422 serial connection it uses.

When it says "RS422" it means "Mesa Smart Serial". Depending on the firmware you are using you might already have smart-serial modules available on certain IO pins. What does mesaflash --hmid give you?

You need some signal-conditioning from TTL to RS422. The easiest would be a 7i74 card, but I suspect that you are trying to keep costs down.

Incidentally, a 7i73 can connect directly to a port on a 7i76E, if the budget stretches.

So the 7i74 could be a viable way to go assuming that I don't have to devote all of P1 to RS-422 ports and would cost a bit less than $90 for the 2nd 7i92.

Budget and space for additional hardware in the cabinet are limiting factors here.

if you just need one 7I73, then a single interface chip (SP491 or equivalent) is all that's needed.

photomankc wrote: assuming that I don't have to devote all of P1 to RS-422 ports

Unfortunately, it does.

A single-channel converter is probably the way to go, as suggested by PCW.

PCW wrote: if you just need one 7I73, then a single interface chip (SP491 or equivalent) is all that's needed.

Ok so that may be feasible assuming that I can work around any pin changes that would happen if I specify one smartserial instance. If that appears on the P2 header it's not going to be worth it. on P1 I can get around it.

If that's not going to work then I may just try the 2nd 7i92. If the PC can handle the care and feeding of two of them then that gives me enough I/O and some encoders to do what I want anyway and the interface is dead simple.

Thanks for the ideas!