Powering on the system 7i92m/7i76/7i76 ?'s

Hey guys,

I am at the final stages and making connections in the cabinet on my VMC and I am a bit confused as to how I sould have the system power on.. Meaning what order... What needs to power on first what is safe to per on together etc..

I am assuming the following:

Computer > Mesa 7i92m (which powers 7i76 & 7i77) > Start Linuxcnc > Power on Machine

Is this the correct order? If not please advise the correct order. I would like to use relays where possible to keep individual switches to a minimum. Maybe power the mesa 7i92m 5v power supply with a relay triggered by the computer power supply so when the computer is started up the Mesa cards are as well. That way once the computer is bored and linuxcnc is started I would just per on the machine afterwards and be ready to go.

Thoughts?

Thanks in advance!

Chris

I don't think the order matters at all except that the 7I92/7i76/7i77 must be powered before you start LinuxCNC
( or LinuxCNC will exit because it wont find the requested hardware/pins )

PCW wrote:

I don't think the order matters at all except that the 7I92/7i76/7i77 must be powered before you start LinuxCNC
( or LinuxCNC will exit because it wont find the requested hardware/pins )

Ok, is just reading in the manual that the 7i92 might do some funny stuff during start up, was trying to figure a way to avoid any thing unexpected happening....maybe I'm misunderstanding it? From the manual:

STARTUP I/O VOLTAGE After power-up or system reset and before the the FPGA is configured, the pull-up resistors will pull all I/O signals to a high level. If the FPGA is used for motion control or controlling devices that could present a hazard when enabled, external circuitry should be designed so that this initial state (high) results in a safe condition.

Sporadically, my 7i76e seems to "freak out" if I power cycle it too quickly during configuration changes. The card will initialize, but I get "pin doesn't exist" errors. Once it's in that state I have to power off for a full minute or so, then the system starts normally.

I'm.not sure what precise conditions cause this trouble loop, but at least I know how to escape it now. It caused me a lot of angst the first time it happened...in thought the card was toast.

DanMN wrote:

Sporadically, my 7i76e seems to "freak out" if I power cycle it too quickly during configuration changes. The card will initialize, but I get "pin doesn't exist" errors. Once it's in that state I have to power off for a full minute or so, then the system starts normally.

I'm.not sure what precise conditions cause this trouble loop, but at least I know how to escape it now. It caused me a lot of angst the first time it happened...in thought the card was toast.

Is this only during configuration changes? And when you say to quickly, what kind of time frame are you referring to? Quick flip of and on or waiting a minute or so? Wanna try and avoid that...lol

DanMN wrote:

Sporadically, my 7i76e seems to "freak out" if I power cycle it too quickly during configuration changes. The card will initialize, but I get "pin doesn't exist" errors. Once it's in that state I have to power off for a full minute or so, then the system starts normally.

I'm.not sure what precise conditions cause this trouble loop, but at least I know how to escape it now. It caused me a lot of angst the first time it happened...in thought the card was toast.

This really makes no sense, can you repeat this and get the exact error messages? Certainly nothing on the 7I76e card has timing constants in the 1 minute range, and I have done LinuxCNC start stop/ power cycle tests 100s of times on the 7I76E without any issues

I suspect you have either a network setup issue or a power issue or a bad 7I76E card, I stand by my statement that the power up order makes no difference as long as the card is ready before you start LinuxCNC

PCW wrote:

DanMN wrote:

Sporadically, my 7i76e seems to "freak out" if I power cycle it too quickly during configuration changes. The card will initialize, but I get "pin doesn't exist" errors. Once it's in that state I have to power off for a full minute or so, then the system starts normally.

I'm.not sure what precise conditions cause this trouble loop, but at least I know how to escape it now. It caused me a lot of angst the first time it happened...in thought the card was toast.

This really makes no sense, can you repeat this and get the exact error messages? Certainly nothing on the 7I76e card has timing constants in the 1 minute range, and I have done LinuxCNC start stop/ power cycle tests 100s of times on the 7I76E without any issues

I suspect you have either a network setup issue or a power issue or a bad 7I76E card, I stand by my statement that the power up order makes no difference as long as the card is ready before you start LinuxCNC

PCW,

so you are saying that it will not effect the machine to turn on power at the same time as the mesa cards even if the I/O's are connected to items that may be triggered by the signals being pulled high? this is where i'm now getting confused. also, is that statement in the manual meaning it will pull high for a brief moment or is this just the natural state after a reconfigure? I'm now more lost than ever.

The FPGA pins are high at startup until LinuxCNC runs. This is expected by all Mesa daughtercards so there is no unwanted I/O activation on power cycles. Also all serial remote devices (this includes the digital field outputs and
analog outputs of the 7I76 and 7I77) disable all outputs at power up or watchdog bite, so you can power cycle however you wish and the outputs will not be enabled until LinuxCNC is in control.

An exception to this are non-Mesa daughtercards (like parallel port breakouts) that may
enable outputs in a undesired way at startup in response to the high output signal.
Parallel port breakout boards with a charge-pump feature do not have this issue.

PCW wrote:

The FPGA pins are high at startup until LinuxCNC runs. This is expected by all Mesa daughtercards so there is no unwanted I/O activation on power cycles. Also all serial remote devices (this includes the digital field outputs and
analog outputs of the 7I76 and 7I77) disable all outputs at power up or watchdog bite, so you can power cycle however you wish and the outputs will not be enabled until LinuxCNC is in control.

An exception to this are non-Mesa daughtercards (like parallel port breakouts) that may
enable outputs in a undesired way at startup in response to the high output signal.
Parallel port breakout boards with a charge-pump feature do not have this issue.

Non mesa cards.. lol are you kidding.. I may be the only guy who has bought enough mesa cards to have stock in the company and still never used one of them to date...lol