Posts made by lee7670

Hello,
It would be extremely useful to support using an absolute linear encoder to close the position loop on BISS-C Absolute Linear encoders as the linear element in a dual loop configuration.

To that end, there is a relatively (~$10USD) affordable IC that is SPI accessible that can handle 2 BISS-C/SSI encoders.
https://www.ichaus.de/product/ic-mb4/
US Sample Shop
https://us-shop.ichaus.com/ProductDetails.asp?ProductCode=iC-MB4-QFN28-5x5-SAMPLE
German Sample Shop
https://de-shop.ichaus.com/ic-mb4-qfn28-5x5.html

In this case, instead of using the duet magnetic encoder on the motor and a quadrature encoder on the load,
you could use either a quadrature encoder on the motor and a BISS-C Absolute linear encoder on the load.
Alternatively, the IC-MB4 supports 2 BISS-C encoders when used with external RS-422 transceivers so you could just use a second absolute Biss-C encoder on the motor itself, so you don't have to phase the motor upon power on.

Examples of BISS-C encoders that are applicable to this use case
Renishaw Resolute
https://www.renishaw.com/en/resolute-encoder-series--37823
RLS LA11
https://www.rls.si/eng/la11-linear-absolute-encoder?

@t3p3tony Running in standalone mode.
2 boards were showing the error when I checked for you. Here's the M122 output.

M105 doesn't output anything because we have no heaters set up.

@droftarts Tried fixing that, no change, running config.g manually reports no errors.

@dc42
Errors persist for a couple of minutes at a time.
They display temperatures of other sensors on the same expansion board, it is intermittent though.
The main board has never had any duplication

I have a temperature sensor array using 1 duet 3 main board and 4 exp3hc boards with PT1000 sensors hooked up to all ports.

Temperature sensors on the expansion boards only (not the main board) seem to duplicate the value of other ports on that board even though they are at very different temperatures.

This seems to be a per expansion board thing so the 3 temperature sensors per board will only seem to sporadically duplicate sensors on the same board.

All boards are on 3.3 stable. I have tried other versions and they seem to do the same thing.

Also, is it possible to have the change the graph temperature range?

Config is below.

; General preferences
G90                                     ; send absolute coordinates...
M83                                     ; ...but relative extruder moves
M550 P"manytempsensors"            				; set printer name

; Network
M551 P""                      ; set password
M552 P0.0.0.0 S1                        ; enable network and acquire dynamic address via DHCP
M586 P0 S1                              ; enable HTTP
M586 P1 S1                              ; enable FTP
M586 P2 S1                              ; enable Telnet

;RTDs
M308 S1 P"temp0" Y"pt1000" A"RTD1" R2200	
M308 S2 P"temp1" Y"pt1000" A"RTD2" R2200 	
M308 S3 P"temp2" Y"pt1000" A"RTD3" R2200 	
M308 S4 P"temp3" Y"pt1000" A"RTD4" R2200	
M308 S5 P"1.temp0" Y"pt1000" A"RTD5" R2200 
M308 S6 P"1.temp1" Y"pt1000" A"RTD6" R2200	
M308 S7 P"1.temp2" Y"pt1000" A"RTD7" R2200	
M308 S8 P"2.temp0" Y"pt1000" A"RTD8" R2200	
M308 S9 P"2.temp1" Y"pt1000" A"RTD9" R2200	
M308 S10 P"2.temp2" Y"pt1000" A"RTD10" R2200	
M308 S11 P"3.temp0" Y"pt1000" A"RTD11" R2200	
M308 S12 P"3.temp1" Y"pt1000" A"RTD12" R2200g	
M308 S13 P"3.temp2" Y"pt1000" A"RTD13" R2200	
M308 S14 P"4.temp0" Y"pt1000" A"RTD14" R2200	
M308 S15 P"4.temp1" Y"pt1000" A"RTD15" R2200	
M308 S16 P"4.temp2" Y"pt1000" A"RTD16" R2200

Ex. 2 different sensors with very different temperatures, but they read the same.

Just set steps per unit to1?

@dc42 is there more detail on how segmentation works? If I pause mid move with segmentation on, move a motor, G92 a couple axes and then resume, will it resume mid segment?

It would be really nice if Duet Web Control could Log the temperatures and positions with timestamps that it receives from the board to a CSV locally on the machine where Duet Web Control is running in the Browser.

Hi, I'm trying to tune a pesky unstable heater. Autotuning is unstable for various reasons, so I am having to tune M307/M301 Parameters by hand.

Do I need to turn off the heater to change the heater model/PID parameters or can I change them on the fly? It's hard to tell whether the new parameters have taken effect.

If I run a M301 to try some Legacy PID parameters and I want to switch back to an M307 heater model afterwards do I need to reset the board before doing that to remove the overrides or can I just send an M307?

@dc42 Thank you, this is very useful!

@dc42 now that 3.2 has been out for some time, would it be possible to get a better description of what the new M307 parameters do? the documentation is very vague and (https://duet3d.dozuki.com/Wiki/Tuning_the_heater_temperature_control#Section_Manual_adjustments_to_the_heater_model_parameters) still refers to the deprecated parameter A (gain). Specifically, heater rate has no units on it. Would it be possible to see a quick diagram of what the heater loop looks like and where all the parameters feed in? I'll need to have one of our controls engineers fix a particularly troublesome heater and it would be good if they had a diagram of what's going on so we can tune on the fly.

@o_lampe You can totally, do that, your stepping just changes the position target. You just have to tune it to react quickly enough, which is the trick... Gotta have a fast ADC and power stage as well as high resolution PWM. Edit: Gotta have a real fast control loop, an ASIC which does it for you (TMC4671 runs control loops at 200KHz according to a webinar I found from the trinamic people), or an FPGA to do similar.

@o_lampe I've done some custom robotics work with the same motors and I was able to get a stable PID loop going no problem in a position mode. Even so, there are also brushed DC motors from reputable manufacturers like Faulhaber which would work great for the purpose.

The TMC4671 (https://www.trinamic.com/products/integrated-circuits/details/tmc4671/) can support steppers, Three-Phase, and DC motors/voice coils all running closed loop with Field Oriented Control for steppers and three phase motors.

Having an expansion board running one or more of these of these drivers with a power stage of 4 half bridges would allow maximum flexibility for motors/feedback.

There are dual feedback inputs so you can have one feedback mechanism for commutation and one for the actual position loop. They support both incremental ABN encoders, Hall sensors, and BISS-C/SSI encoders.

This would allow you to drive essentially any motor in step/direction mode from a duet.

Sweet tiny extruder with a micro geared dc motor for the smallest direct drive possible (https://www.pololu.com/product/3055)? You got It!

Drive a linear motor for the absolute fastest speeds for benchy printing? You can do it!

Motor torque feedback for extruder pushing force tracking and grinding prevention? Totally doable.

Want to drive a voice coil optical stage that you got on ebay just because? Easy.

Got your hands on some optical scales from a CNC and never want to use limit switches again? Sure.

That's a lot of functionality for a 12USD chip...

Hello, I have an application that requires many axes of motion (>25) and I know RRF 3.3 beta 1 recently enabled 15 axes on the duet 3 MB6HC with expansions, is it possible to increase this limit even more?

Thank you.

@dc42 said in Does anyone use M120 or M121?:

M120

Yes, I use it for certain operations not controlled by duet macros where I need to save system state before executing commands from remote sources.

Hi, it would be nice to set up non-heater based temperature alarms for things like motors using M143 that aren't tied to a specific heater, only a temperature sensor. It would also be nice to have the option to pause the current print instead of just shutting the printer down on an overheat.

I know this could probably be done using daemon.g and some meta gcode, but that seems highly inelegant and the code to monitor temperature and fault out is already there for monitoring heaters.

Hi, for various reasons, I have had a couple tuning cycles that have taken >1.5 hours. Would it be possible to limit how many cycles it can perform or what the threshold for convergence is?
I am on 3.2 release.

Beautiful, thank you!

Hello, when will the STEP file for the duet 3 mini ethernet be available?
I do not se a repository on the Duet3d Github.
Thanks.