meindert.norg

LS, At the "See Also" section of the GATHER function on Page 303 in the [url=http://www.deltatau.com/manuals/pdfs/TURBO%20SRM.pdf?id=634305158885508733]Turbo PMAC/PMAC2 Software Reference[/url] a reference to "Data Gathering Function (Analysis Features)" is given. Where can I find this info on "Data Gathering Function (Analysis Features)"? regards, Meindert

LS, Is there an easy way to calculate and plot the frequency response (bode plot) of a controller, using the controller I-variables? For example, I can see that the I-variables file can be read into Matlab, and using the clock parameters and PID parameters, the controller frequency response can be calculated and plotted. Did anyone already do this, or something similar? regards, Meindert

Richard, Thank you! I knew about the Servo-IC #2, but totally missed the UMAC suggested list in the Turbo SRM. I was working with the Turbo PMAC2 list. Regards, Meindert

LS, I have a Turbo PMAC2 system with an ACC 24E2A (2 axes expansion board). I have 2 motors connected to this ACC 24E2A. When I want to know the actual motor 2 position, I check M626 which is linked to [b]Servo IC 0[/b] channel 2: see the suggested M-variables: [quote]; Servo IC 0] Registers for PMAC2 Channel 2 (usually for Motor #2) ; Motor #2 Status Bits M262->D:$00010B ; #2 Actual position (1/[Ixx08*32] cts)[/quote] However, when I connect a user-bit to the front-panel flag connectors on the 24E2A (USER2), I need to read M1015, which is the USER2 flag input of [b]servo IC 2[/b], channel 2 (the suggested M-variables list indeed suggests that this is the First Acc-24 channel 2). [quote]; Servo IC 2 Registers for First Acc-24 Channel 2 (usually for Motor #10) M1015->X:$078208,19 ; USER2 flag input status [/quote] Why is the #2 Actual position information available on [b]IC-0[/b], ch2, and the flag information on [b]IC-2[/b], ch2?

I experienced a weird behavior that I finally was able to explain. Observations: [list] [*]A audible 'click' from the motor every (approx.) 1 second [*]After turning a motor off (#2K), that same motor was enabled within (approx.) 0.5 second (this was what really freaked me out....) [*]I had no PLCs or motion programs running. [/list] Cause: [list] [*]A $7820A entry in a Watch Window [attachment=1422:name] [/list] Background info: [list] [*]Over the past few weeks, while getting to know the Delta Tau controller architecture and software, I added several entries to the Watch Window, never deleting the old entries, unless I needed some space in the window. [*]During my experiments, I apparently entered a memory address ($7820A) instead of the M1002 variable which is the suggested M-variable for this memory address. [/list] Solution: [list] [*]Removed $7820A entry from watch window. [/list] Discussion: [list] [*]I'm not sure what having this entry in the Watch Window does, but it seems as if a pulse of is generated on the controller output, forcing the motor to move slightly. [/list]

Hi Jeff, Thanks for your reply. Although I did find a few new articles on the announcement of this PMAC Servo Analyzer SW package, I was unable to find the SW itself on your website. Can you tell me where I can find it, and if there is a charge for it?

Charles, Thanks for your answer. I appreciate the code examples very much, because for me that is an excellent way learn about the possibilities of the code. Do I understand correctly that there are currently no tools (like the trace and tuning tools) available to perform a frequency response measurement? Are there any plans in the making for making such a tool available? regards. Meindert

Hi Sina, I'm not sure how to respond, because I'm not familiar enough yet with the compensation tables and bias that you mention. However, I understand you're still using location B for something. As I mentioned earlier, location B is unknown. I would like to see if the procedure as I described it can be implemented, (1) to get a better understanding of the possibilities of the Delta Tau architecture and (2) because I am planning to use the implementation for [b]action V [/b] of the procedure for an application of which I can-not post details in this forum. Thanks, Meindert

Great! Thanks. Meindert

Hi Sina, Thanks for thinking outside of the box. However, I'm really looking for a solution for "action V" as described above. Let's just say that the location of B is unknown. regards, Meindert

LS, I noticed a "Sine Sweep" function in the TuningPro software to measure frequency responses. However, it seems that the sine can only be 'injected' into the setpoint. In most applications, a servo can follow a (e.g.) 1 Hz sine-setpoint of (e.g.) 1000 increments, but not at 100 Hz. The result is that I can only measure very small frequency ranges in one measurement. One could solve this (I guess) by selecting several frequency ranges with decreasing amplitudes values, and 'merge' the measured results manually, but I have not tried this. Does Delta Tau have a tool available to measure frequency responses by injecting a sine or even noise into the controller output signal? Or even a tool that scales the injected signal based on the size of (e.g.) the following error or control effort? Thanks for your input. regards, Meindert

LS, Searching for information on this forum I received the following error: "[i]Sorry, but you can only perform one search every 60 seconds. Please wait another 50 seconds before attempting to search again.[/i]" Question: why is there a limit in how fast one is allowed to use this great source of information? If I get no answers to a search, I rephrase and try again... normally. regards, Meindert

All, I need help implementing the following function. I called it a "catch the egg"-move. The function goes as follows: A motor with normal feedback needs to move from A to C as fast as possible. Because of varying friction between A and C, the maximal allowable velocity is determined by the highest level of friction. Let’s say that is at location B. If we’d want to go faster, we would get a servo error while passing location B. In case of the ‘catch the ball’-move, [list=1] [*]first we start a normal move ([b]action I[/b]). [*]After leaving A, and accelerating to a certain speed, the motor is placed open-loop (while maintaining the controller output at that time, let’s say 7.56 V) ([b]action II[/b]) [*] and the controller output is ramped up to the maximum value (let’s say 10 V) ([b]action III[/b]). [*]At this point the motor is moving as fast as it can, slowing down and speeding up as friction increases (location B) and decreases. When approaching C, we ramp down the controller output to (e.g.) 9 V ([b]action IV[/b]) [*] and ‘catch the motor’ by closing the servo-loop while generating a setpoint that is identical to the current position/velocity ([b]action V[/b]) as to prevent any sudden jumps in the controller output. [*]After this we decelerate to zero velocity and arrive at point B ([b]action VI[/b]). [/list] The name "catch the egg" of course comes from the movements one would make trying to catch an egg that was thrown at you: attempt to match the egg's position/velocity with your hands before grabbing it. I believe actions I-IV are doable, but for action V I ask your input. (heck, if someone wants to write the programs for all actions, go right ahead...) I'm looking forward to any input related to this problem. regards, Meindert

Hi all, I would like to execute moves and define traces (gather data) on a Turbo PMAC2 from Matlab. Does anyone know how to do this? Maybe download a motion program from Matlab (and start it) and define traces (and retrieve the data) into Matlab? Maybe a direct way to use a serial-port communication to enter motion commands, just like what is possible from the terminal in Pewin32PRO2? My ultimate goal would be to perform fully automated motor-calibrations or frequency response measurements from Matlab. Thanks for your input. regards, Meindert