[jmelson]

It has been quite some time since I did this, so my memory is a bit vague. But, looking at the code I wrote, it appears the data
is at 1 Mbit/second, and I think the first 3 bits are the Hall signals, and the next 3 are the complement of the Hall signals.

Jon

[gm276]

I hooked up a usb converter that can do 1M serial. Sent the output to a 75als191 differential driver and tried to feed the REC leads on the panasonic drive. . still get encoder error.
Out of ideas. Perhaps my inter character time is too long. I was sending and ascii ctl-g or a "c" to simulate the commutation signal.
Anyone actually know what the Pansonic drive wants to make it self happy?

[jmelson]

I hooked up a usb converter that can do 1M serial. Sent the output to a 75als191 differential driver and tried to feed the REC leads on the panasonic drive. . still get encoder error.
Out of ideas. Perhaps my inter character time is too long. I was sending and ascii ctl-g or a "c" to simulate the commutation signal.
Anyone actually know what the Pansonic drive wants to make it self happy?

I'm a little vague on this, but my recollection is that the first 3 bits are the 3 commutation signals, then the next 3 bits are the
complement of those signals. I don't recall, but I don't remember that there was any parity bit on this. I think it
was an 8 bit byte with probably 2 stop bits. if this isn't enough to get you going, I could scope it out, as I use
a MUMS motor to test my converters.

Jon

[gm276]

Jon,
I would love to know what the MUMS puts out. I wonder what the differential voltage needs to be (now putting out 0 volt and 5 volt). Parity or not. Least significant bit sent first?
Inter character time? Thanks for any of your info.
Don B in pa

[jmelson]

Jon,
I would love to know what the MUMS puts out. I wonder what the differential voltage needs to be (now putting out 0 volt and 5 volt). Parity or not. Least significant bit sent first?
Inter character time? Thanks for any of your info.
Don B in pa

OK, I'll try to get a scope on it this weekend. It is 5 V differential, as in 26LS31 / 26LS32 type drivers.

Jon

[gm276]

Jon, I think I have it.
After a bit of head scratching and some time with the scope.
bits 1 2 and 3 are the hall states. bits 4 5 and 6 are the complements of the hall state but in reverse order.
bit 7 is set and tells if there are one or two hall state on. bit 7 set to 1 if two hall states at once.
the bit rate as you said, 1 megahertz. The character rate 83k.
Thats what I see with the scope.
Regards,
Don B

[gm276]

Jon,
I managed to get my own mums motor. So all of the above was from observation of the rx leads.
Don B

[jmelson]

Glad you were able to figure this out! I didn't know about the reverse order of the complement bits, I didn't use those
in the converter I made. I'm guessing bit 7 is a parity bit.

Have you gotten something to work with your drives, yet?

Jon

[gm276]

Jon,
No, starting to think the drives are bad. ERROR 22
I am waiting for some connectors but I did hook up the output of the rx leads from the mums motor and still the error persisted.
I will try once more with some better cables.
Don B

[jmelson]

Well, are you sure the drive supports the motor you are trying to connect? I've never worked with the Panasonic
drives, I just got some motors cheap on eBay quite some years ago. I make my own brushless drive system.

Jon

[gm276]

A better day today. Got the servo drives in the green !
Wired a non MUMS motor except for the RX (since this motor has none) then I pumped in the output of a real mums motor to the RX on the drive.
Next step to create an artificial RX signal.
Don B

[jmelson]

GREAT! Now that you have a motor there with the right protocol, you can examine it at your leisure, and it proves
your drives are OK, too.

Jon