Communication Error Message

Hello,
sometimes, especially when I move the axis with the arrowkeys, the display shows the following message:


Does some knows what can I do against this?

Thanks

Hans

Have you run a latency test on you PC?

If you have bad latency issues you may have a watch dog bite
which will stop all serial comms (and generate a slew of error messages)
You can check this by looking at the watchdog_has_bit pin after you get
these error messages. if its set (true) you have a latency issiue


Its also possible that you have a 5V power issue at the 7I77
This can also typically cause this kind of loss of communication

Normally 7I77 5V power should not come from the FPGA card
as there will be too much current once enough encoders are connected
This means:

5I25 W2 DOWN
7I77 W5 RIGHT
External 5V power source to 7I77 TB1

Hello,
I have an external power supply. What units get voltage from this connector? The powersupply can give 2Amp.

Thanks

Hans

Holzwurm56 wrote:

Hello,
I have an external power supply. What units get voltage from this connector? The powersupply can give 2Amp.

Thanks

Hans

Typically you use two seperate power supplies.
5vdc used for encoders and I dont know if anything else on the board uses it
Field voltage power, which is used for logic on the board and/or I/O, this is typically 12 to 24VDC
You can go a step further and split you field votage power so power from the logic board is seperated from the power going out into the field.

Is it possible you have a loose connection?
Those errors look like you totally lost connection to the 7I77

What LinuxCNC version are you running?

If this happens again can you post your dmesg log here?
(so all errors can be seen )

Hello,
I use two separate power supplies one with 5V and one with 24V.
I use Wheezy with LinuxCNC 2.7.

Thanks

Hans

That really does suggest that there's a loose connection or power supply issue

Things to check:

5V at 7I77 is OK (measure when jogging)

5I25 and 7I77 power options are right (5I25 W2 DOWN 7I77 W5 RIGHT)

Cable from 5I25 to 7I77 is secure and IEEE1284 compliant

No bad latency issues (run servo thread only latency test for an hour or so while "torturing" PC)

Post dmesg results here after you get the error (so all errors are available for analysis)