DRO values not zero on startup

I tried entering the line into the sample config that you provided and yes, the problem happens there too. It doesn't matter what the name of the signal is, if I link a signal to the rawcounts output , the DRO is messed up on startup.

Agreed, I have an unusual setup - I only have the 7i76 in there due to my lack of understanding of all the machine control concepts when I was starting out and the encoder on it proved useful for the MPG. I have a plan to add rotary encoders for each axis to improve the machines accuracy, which would use the remaining three encoders on the 7i77, so I decided to use the additional encoder on the 7i76.

I will modify the config line - it was created by PnCConf and I only really noticed what it was doing when I went through the HAL and ini files in more detail looking for this problem last night.

How is the MPG connection configured using the built in support? I see it mentioned on your website, but can't find anything about it in the manual. If I can get things configured correctly and take the 7i76 out of this machine then I may well use it in something else in future.

In case you hadn't noticed, this is still very much a work in progress, with me gradually climbing the learning curve!

Ah - I've just taken a look at the latest version of the manual and found the part about the MPG connection - it's not in the version of the manual I was using.

Is this a new feature of the 7i77/7i76 - was it there all the time, or is it enabled with a firmware update?

Thanks

Ben

Its relatively new (say last year or so)
It needs to be enabled by setting the sserial mode
to the mode listed in the manual

Yes, I see that it has to be in Mode 3 - is this supported on my older 7i77, as the older manual (v1.5) only list modes 0-2?

Ben

Not sure. With linuxcnc 2.5.x you would just have to try.
If you run LinuxCNC master, it will display all the available
modes in the kernel log (dmesg)

I should add that with master, you can upgrade the sserial remote
firmware to the latest

Ah - now that sounds useful - especially as I already have Master installed for testing with Gmoccapy.

Could you point me in the right direction for the instructions on how to set the sserial mode and how to update the firmware?

Thanks

Ben

www.mesanet.com/software/parallel/sserial.zip
Has the sserial update scripts and firmware images for
all Mesa's sserial cards
(in utils/linuxcnc)

The mode is set in the sserial_port_0=abcdexxx config token
a is sserial channel 0's mode, b is sserial channel 1's mode etc
(man hostmot2)

Ok, I think I have the latest firmware already - I did update it a few months ago and when I ran mesaflash with the --verify option against the latest firmware today it checked out ok.

I've also read the man pages for hostmot2 and it seems that I need to use sserial_port_0=30000xxx to load in mode 3. Is that correct? It seems to load ok with that setting and if I try 4 instead of 3 as a test then it does fail.

Many thanks for your help.

Ben

Mesaflash can check FPGA firmware but not sserial remote firmware
The README file has the instructions for updating the remote sserial device firmware

Thank you Peter

You've been very helpful. I see some re-wiring in my near future - both physically and logically!

Ben