MpAxisBasicConfig Homing Parameter Minimum return distance

[Frederico_Mantovani]

Hi

have an axis application in which I’m using the mcHOMING_BLOCK_TORQUE homing procedure.

I’ve configured and tested it, and everything is working correctly so far.

The drive configuration in AS:

• My AS Version: 6.5.1.7
• mappCockpit Version: 6.5.0
• mappMotion Version: 6.5.1

I’m now trying to adjust the homing parameters using MpAxisBasicConfig.
I have already implemented this function block, and I use it extensively across all my axes.

(As a matter of fact, when the machine powers up, I first perform a read operation to retrieve all current parameters and populate the data structure. After that, I only modify the parameters I actually need to change.)

For the homing configuration, I’m able to manipulate all parameters except the Minimum Return Distance. And that’s where my issue lies…

According to the help documentation, the Minimum Return Distance parameter is used when the Reference Pulse is Not Used (mcSwitch_OFF).

The explanation of when it is in mcSwitch_OFF:

The table shows that the variable “ReferencePulseBlockingDistance” seems to be used for both “Reference pulse blocking distance“ and “Minimum return distance“:

Then, I also checked the MpAxisBasicConfigType:

With this information, it seems reasonable to assume that I should be able to set the ReferencePulseBlockingDistance parameter when using mcSwitch_OFF, and that this value would then be used as the Minimum Return Distance.

However, when I download the drive configuration — as shown in the first screenshot — I can see in mappCockpit that the parameter is configured correctly:

Then, when I execute MpAxisBasicConfig with the updated value for ReferencePulseBlockingDistance — for example, 6.0:

I get the following result in mappCockpit it goes to 0:

Out of curiosity, I then changed the Reference Pulse setting to mcSwitch_ON, and in this case the drive correctly accepts the value I write.

However, as soon as I switch it back to mcSwitch_OFF, it stops accepting the value again.
Obviously, I cannot keep the Reference Pulse set to mcSwitch_ON, because it does not achieve what I need, which is to return 5.0 mm after the homing process.

I would appreciate some help understanding whether this behavior is a known characteristic of the system, a limitation, a bug, or something related specifically to how MpAxisBasicConfig handles this parameter.

Additionally, I’d like to know the recommended way to work around this issue.

Thanks in advance.

[valerio.manenti]

Hi @Frederico_Mantovani ,
sorry but I don’t have the hw to reproduce your issue at the moment, BUT if you think there is an issue on MpAxisBasicConfig, as work around you can override the homing pars with MC_BR_ProcessParam

Changing settings at runtime

I have forwarded your question to colleagues in Brazil so in case they will reproduce the issue, they will create a CASE for R&D

Final note Frederico, in case you want to keep the new settings after warm restart you need to call MC_BR_ConfigParam too

Ciao
Valerio

[michael.bertsch]

Hello,

I think this is a issue in the system at it is not working as supposed to.

Just another idea for a alternative solution:

The MpAxisBasic Function block was extended to supply all homing Parameters.
I don’t remember the version, but as you are using the lates one, it will be in there.

If you call your home function in the Application, just switch from mcHOMING_DEFAULT which adresses the Parameter in the Configuraion to the mcHOMING_BLOCK_TORQUE at the MpAxisBasicPar - Structure and set up all other Parameters there.

Greetings
Michael

Hello,

Just as an Update, MC_BR_ProcessConfig does work in ArSim.

So it is not the Configuration Functionblock in Generall which has an issue but more the MpAxisBasicConfig alone. I will go to check this next.

Greetings
Michael

Hello,

I have created the German CASE-71196, you can use it for you local collegues as a reference if they create a own CASE to keep you on track of the solution process.

I think they missed to switch in the MpAxisBasicConfig Functionblock to this other Parameterline. We can see in the picture that both Load - Commands resulted in different Values.

Greetings
Michael Bertsch

[valerio.manenti]

Thanks so much Michael for your help, unfortunately we don’t have visibility on your CASE pool, but for sure they can use that as reference.

If you have news please update @gabriel.costa

Thanks
Ciao
Valerio

[michael.bertsch]

Hello,

CASE-71196 → “QCAS-4692 - MpAxisBasicConfig does not correctly load and save the homing parameter structure “Reference pulse” and its sub elements”
is sheduled to be solved in mappMotion 5.31.0 / 6.7.1; These Versions are sheduled to be Released around 1.6.2026. If PreReleases are Required please contact your local support.

Greetings
Michael