thinking of trying my ASUS Q87M-E motherboard

PCW wrote:

Unfortunately the 5I20 is so old the pncconf support for it has been dropped

just wanted to comment on this point.
the 5i20 may be old, but according to the Mesa store, it is still made, and sold. why would the support be dropped, if it is still available. to me, that feels like buying a new/used car from a dealer, and having no warranty, just because the model is old, even if it is still produced by the factory.

i mean, the 5i20 seems to me like a good entry-level card, into the world of Mesa, as it has plenty of I/O, and being an older model, the price is far cheaper than say, a 6i68, with a 3X20 ($377 + $99 = $476). the 5i20 sells new for $260. in any case, i don't think support should have been dropped for a currently produced card.

i don't know the full details of why it was dropped, but this is just my opinion.

~Travis

Not sure why the 5I20 was dropped from pncconf, but the card itself is no longer produced
except by special order as them PCI bridge chip and FPGA chip are obsolete.

A 5I24 (PCI), 6I24 (PCIE), 7I80HD (Ethernet) or 7I90HD (EPP/SPI) are all far cheaper and more capable.

As I mentioned, there is a sample config for the 5I20 built into LinuxCNC which can serve
as a starting point. The firmware can be installed with the package manager or apt-get
or as I mentioned you can install them by hand from the 5i20.zip file (the firmware files
are in /configs/hostmot2) and have a file extension of .bit

PCW wrote:

Not sure why the 5I20 was dropped from pncconf, but the card itself is no longer produced
except by special order as them PCI bridge chip and FPGA chip are obsolete.

Hmmm, i assumed they were still current as they were still listed for sale.

A 5I24 (PCI), 6I24 (PCIE), 7I80HD (Ethernet) or 7I90HD (EPP/SPI) are all far cheaper and more capable.

i had not realized they were so inexpensive. i was under the impression they were all $300 and up, so i checked prices, and promptly bought a 7i80HD-16. bit of an impulse buy...
i was stuck between the 7i80HD-16 and the 7i80HD-25, but didn't know what the difference between them was, so i got the 16, as my account could currently afford it. i liked the ethernet card idea, as the computer to card interface should remain viable for future PC upgrades, unlike PCI, and potentially PCI-E, in the far-future. it will also get rid of the mess of cabeling, by allowing me to tuck the electronics somewhere under the machine, and only have to run a ethernet (and power) wire.

As I mentioned, there is a sample config for the 5I20 built into LinuxCNC which can serve
as a starting point. The firmware can be installed with the package manager or apt-get
or as I mentioned you can install them by hand from the 5i20.zip file (the firmware files
are in /configs/hostmot2) and have a file extension of .bit

ok, thank you!

i look forward to the arrival of my new 7i80HD-16, and will use my 5i20 to test between my machine and computer, to make sure i have things right before the 7i80HD-16 arrives, even though the pinouts may be different. worst case, i can frame the 5i20 as a point of history, and as a reminder to do better research before buying old hardware... or i suppose i could sell it to somebody that needs a backup for their current 5i20...

anyway, i hope i am moving in a positive way now.

~Travis

tommylight wrote:

You could have asked ....

yes, but i am well known for asking the wrong questions, when it is too late anyway...

To late, but might get handy next time.

too late? what did i do this time? was the 7i80HD-16 not a good purchase? or is it a reference to me buying the 5i20 with little to no research?

~Travis

Thanks! it is great to know i finally made a good purchase

now, regarding the 7i80HD-16, my impression of the manual is that it is best with an I/O voltage of 3.3V.

The FPGA used on the 7I80HD has a 4V absolute maximum input voltage specification.

i realize it is 5V tolerant, but should a component fail, it could fry the FPGA when 5V passes into it. so unless i use a Mesa daughter card (7i37TA, or 7i42TA), if i make my own daughter card circuits, would it be safer to limit interface voltage to 3.3V, or are my concerns un-grounded?

my stepper drivers have built in opto-isolation, and the relay boards i have are opto-isolated as well (5V input, though... may re-think the 3.3V theory). so the only I/O i need to protect is the digital inputs for limits, and so forth.
i am leaning toward the 7i37TA, when i can afford some, so the above may be a mute-point anyway. kinda thinking out-loud here anyway.
my "play" budget is kinda dead for a while, except for small stuff, so i may start with a direct-connect method to the 7i80HD-16, with the "safe" components, and use some of the opto-isolator chips i have on hand to tie in the home and limit switches, and the E-STOP button. i can configure and wire things according to the assumption of using a 7i37TA daughter board on each port, so it won't require a re-write of the HAL configs. that way i can just move the wire connections over, and be back up and going. though if my DIY protection circuits work, maybe the 7i37TA boards will be unnecessary.

anyway, i will mentally hash out the details, rather than plugging up this forum.

~Travis

As Tommylight says, you _can_ drive I/O devices directly from the FPGA
card but you need to be careful. The most common issue we see is cards
that have the low side ESD protection diode in the bus switch or FPGA fried,
shorting that pin to ground.

This is easy to do by simply shorting a I/O pin to frame ground in a working
machine (that may have 1-2V of AC high frequency noise between different points)
This will cause a current high enough to damage the low side diode to flow.
You can avoid most of this kind of damage by using a series resistor to limit
negative input currents. The 7I80 is OK with up to +7V inputs (the bus switch
simply turns off at voltages > 3.3V or so) The 5I20 has a +5.5V maximum input.
Both have a ~-0.7 V maximum because of the input ESD diodes so that is
usually the weak spot (the diodes will only take about 10ma)

ok, that settles it, i will save for Mesa daughter boards. they are expensive, but cheaper than a new 7i80HD-16.

i was playing with pncconf, in regard to the 7i80HD, and when i select 0 encoders, 1 PWM (for my laser head, when it comes from China...), and 4 stepgen (3 axis + charge pump), it sticks the stepgen pins way off on connector 3, PWM on connector 1, and the rest of 1, and 2 are all inputs. i think there were enough outputs on connector 3 for my needs.

i still have to remember how i got my LHB04 USB pendant working. i found my post on here, but i wasn't very specific on what i did to get it to work. i know i have to get the LinuxCNC source to compile in the module, and i should also get an up-to-date copy of the LHB04 driver source. perhaps this time i will take better notes on how i get things working, for future reference.

~Travis