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[Solved] Reading Current Controller Ki Gain (UART Command 0x92)


Forum 1
 Eric
(@ecp)
New Member
Joined: 3 months ago
Posts: 4
Topic starter  

Hi ...

I am interfacing to a Solo Uno by a rs232-ttl serial port on my controller and am reading back all the registers.
Compared with the same values as displayed in the Motion terminal they all match, except for 0x92 : Current Controller Ki Gain.

The Motion Terminal displays the Current Ki value is: 0.006923076625
However when read via UART command 0x92 I get 0x0114EC4E.
This is documented as a Sfxt(32-17) parameter a which maps to 138.4615325.

This UART readback value is 20000.0x larger for current-Ki than read by motion terminal.

a) Is this expected behavior? I could not find mention of it in the document.
b) If so, would an inverse scaling factor of 1/20000.0 be required to set this register via UART Command 0x18 : Current Controller Ki Gain?

Thanks
Eric


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Forum 1
 Eric
(@ecp)
New Member
Joined: 3 months ago
Posts: 4
Topic starter  

Hi ...

On a related note of controlling the Solo Uno by Rs232-ttl *and* monitoring via USB with Motion Terminal,

I would really like to get some data charts generated while running the system under Rs232-ttl control.

c) Is it possible to get Motion Terminal as a debug instrument (like an Oscilloscope) with it connected to USB generating a graph,
while operating the solo Uno as part of a bigger system via serial? (ie: dynamically updating 0x04 : Torque Reference)

d) Can I get a pointer to a reference or guide on using Motion Terminal as a monitor while operating the Solo Uno via Rs232? (ie how does the Solo Uno
respond when commands are coming in from both Serial and USB?). I often operate with both connected as I debugged my software, and it sometimes works.

Thanks again

Eric

My hardware and firmware versions are:

0xA2 : Firmware Version =     241673 [0x0003B009]
0xA3 : Hardware Version =  268496898 [0x1000F002]

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SOLO Team
(@milad)
Chief Member Moderator
Joined: 2 years ago
Posts: 395
 

Hi @ecp,

Posted by: @ecp

a) Is this expected behavior? I could not find mention of it in the document.

Yes, that's correct and the datasheet should be updated for that, actually, 1/20000 is the sampling time that the Ki is tuned for a specific bandwidth.

Posted by: @ecp

b) If so, would an inverse scaling factor of 1/20000.0 be required to set this register via UART Command 0x18 : Current Controller Ki Gain?

Yes, and it will be added in the near future, thanks for bringing it up.

Posted by: @ecp

c) Is it possible to get Motion Terminal as a debug instrument (like an Oscilloscope) with it connected to USB generating a graph,
while operating the solo Uno as part of a bigger system via serial? (ie: dynamically updating 0x04 : Torque Reference)

unfortunately as of today the only way to monitor some parameters in the Motion terminal is by using the Monitoring Mode, however, depending on what type of system you are using, you can use our Python library to make the program do any arbitrary action, in near future, we are releasing supports for Simulink and Labview where you will have far more freedom to interface SOLO and monitor signals

Posted by: @ecp

Can I get a pointer to a reference or guide on using Motion Terminal as a monitor while operating the Solo Uno via Rs232? (ie how does the Solo Uno
respond when commands are coming in from both Serial and USB?). I often operate with both connected as I debugged my software, and it sometimes works.

SOLO will respond back only on the line that it received a command, so if you send the Monitoring request ( or any other read/write) request through UART, SOLO will answer back through UART and vice-versa, so it's better if you are using Monitoring Mode, just only using one of these lines, but if you are sending various Read/write commands you can switch dynamically between UART or USB, the document that tries to explain related points to this subject is our USB-UART user manual for the moment, let me know if you have other questions.

Milad

If you found the answers helpful and you could solve your problems, please kindly verify here to help others in the future.


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