IDX 7505 positioning control via RS485

[Vic]

Hello,

I have an application wich require to contorl a stepper motor via serial communication (RS485), I've bough a IDX 7505 for this porpose, and now I have some questions:

#1. About the acceleration parameter, I see in the manual a range from 0 to 250000, could you pls explain what does it means exactely? I mean what are the units? pulses/second? I would like to know the magnitude.

#2. My hardware is already connected and also connected to a hyperterminal, and the motor works fine, I mean the driver execute the orders received via RS485 from the hyperterminal, I'm using a QSH-5718-55-30-098 stepper, I'm reading in the manual of the motor and in the driver IDX 7505 as well that the maximum speed for a motor like that is 20 turns/sec who is equal to 4000pps from the driver, but as soon I'm near 10 turns/sec, the motor start to make strabge movements or jumps and begins to lose steps until stops. I'm working in a normal default mode for chopper and NO stallGuard, could you pls. explain what is happening and it's solution?

#3.The main porpose for my application, as I said, is to control the position of one axis, so I can't find information how I can set a value of position, for example 435steps that is equal to a 43.5mm in my mechanical application, The idea is to do so just sending the right orders via RS485 and the motor must run until reach those 43.5mm. Can I do this? how? I've trie with the commands P and R but the P command seems like is to set the internal counter of steps of the driver to a desired value, and the command R is just returning via RS485 the actual position or step counter, but what I need is to tell the driver how many steps have to move and then stop until next order of movement.

Pls try to answer and support me as soon as possible, I'm not an student and this is a professional or industrial application that I'm developing.

Thanks.... Victor

[Olav Kahlbaum (TRINAMIC)]

1) The unit is 28.96 µsteps/s^2 * parameter_value. Please see also chapter 5.8.1 of the manual.

2) It seems that you need more current. Please use the C command to increase the current (to up to 100%).

3) The IDX module (and also the TMCM-013 and TMCM-078 modules) is mainly meant to be a step/direction unit. So it does not have a positioning command. The only way to do positioning with the IDX module is to control it via the step/direction interface (e.g. using a TMCM-342 module). Or use one of our other modules instead, e.g. the TMCM-1060 or TMCM-1180 module.

[Vic]

Thanks for the pront replay, however I still have some doubts refer to the points:

#1. so from your answers it seems like the parameter of acceleration have uSteps/s^2 right? and the value can be setted from 0 to 250000, but the acceleration time is different depends on the speed value, I mean if I set for instance AA500, the time that needs to reach the maximum speed is different if the speed is set to AV50000 compare to the AV100000, sorry but there is something that I don't understand. Can you write me a clear example?

#2. I'm testing the motor and driver in the workbench with a power supply of 24V/10A, and following the manual instructions, I set the AC parameter to a 60% due to my motor is a 3A (QSH-5718-55-30-098), and during the functioning of the motor I see in the ampmeter 1.3A at such speed, so I don't understand why I have to increase the AC parameter. Could you pls. give me more details about?

#3. Okay, so for whatever reason the sales told me that I can do that with this IDX driver, anyway you told that I can do positioning control by using step/direction, could you pls. explain it how? could you pls. give me an example?

Thanks again ....Victor

[Olav Kahlbaum (TRINAMIC)]

1) No, I meant (28.96µsteps/s^2)*value. So when you set it to 1, you will have 28.96µsteps/s^2, and when you set it to 1000, you will have 28960µsteps/s^2.

2) Which choppering mode are you using? For high speeds it is best to use mode 0.

3) For step/direction operation you need a module that generates step/direction pulses (like the TMCM-342 module). This then has to be connected to the step/direction inputs of the IDX module. The motions of the motor are then no longer commanded via the RS485 interface of the IDX module, but through one of the interfaces (RS232, RS485 or CAN) of the TMCM-342 module.

But I would better recommend using our brand new TMCM-1060 or TMCM-1180 module for your purposes. They are equipped with our new motor driver chip (TMC262) and can do all these things in a much better way.

[Vic]

1) OK.

2) I'm using mode 0, I already read the manual. However the motor lose steps and I don't know why, I have much more current in the power supply that the motor or driver is asking for, also I tryed with slow speeds ad still some steps missing (by the way, the motor is without load) PLS. I need help on this or I'll reject Trinamic for this project with big potential of sales for your company. This kind of support is too slow or unacceptable for a industrial or professional applications. I already lose 3 days for those short questions probably easy to fix in a 10 minutes phone call..

3) Mr. Simone from TD Elektronics (your disributor at Italy) recommend me the IDX 7505 when I explain it him the needs of the project, and now I have to buy annother reference, this is really unacceptable for that error I already spend money in a reference that is not fitting properly to my needs. What can I do now?

[Olav Kahlbaum (TRINAMIC)]

Sorry, but the new modules I mentioned will suit your needs much better, because they are very good for fast motor speeds and they also have positioning commands (TMCL).

[Vic]

Okay Olav,

This is already clear, for my application the best module is TMCM, but in any case what is the support for the one I have??

I still have no answers from you about topic number 2, My motor is losing some steps and is without load with the right current.

[Olav Kahlbaum (TRINAMIC)]

The IDX module is not best suited for such high motor speeds, it is mainly made for fine microstepping. This will be much better with the TMCM-1060 for example, which can do both: fine microstepping (up to 256 microsteps) and high motor speeds (tested with speeds of up to 80rps).

[TRINAMIC_GG]

Dear Victor,

obviously your distributor recommended you not the best solution for your application.
You should contact your distriubutor and ask to change the product.

The IDX is definetly not usable in high speed applications!

You should defininitely try out the TMCM-1060 or TMCM-1180 as recommended.

It makes no sense to try to use the IDX with this type of applications.

Best Regards, Guido