How to read hal pin from embedded panel from an other component

newbynobi
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5 years 7 months ago #202493 by newbynobi

How to read hal pin from embedded panel from an other component was created by newbynobi

This might be a very complex question or just a very simple one.

I want to build a universal debug panel as embedded tab. As the panel should be universal and should be able to show also hal pin from other components, I need to get the component hal pin.

If I do this code in the py file of the embedded tab called "debug_panel", embedded in gmoccapy:

Code:

print(hal.component_exists("gmoccapy"))
print("gmoccapy = ", hal_glib.GComponent("gmoccapy"))
print(hal.component_exists("debug_panel"))
print("timer = ", hal_glib.GComponent("debug_panel"))
print(hal.component_exists("abs"))
print("abs = ", hal_glib.GComponent("abs"))
print(hal.component_exists("motion"))
print("motion = ", hal_glib.GComponent("motion"))

I get True for gmoccapy, debug_panel, abs and False for motion.
The strange is, that I get for all components the same ID, something like this:

Code:

True
('gmoccapy = ', <hal_glib.GComponent instance at 0x7f07ac079200>)
True
('debug_panel = ', <hal_glib.GComponent instance at 0x7f07ac079200>)
True
('abs = ', <hal_glib.GComponent instance at 0x7f07ac079200>)
False
('motion = ', <hal_glib.GComponent instance at 0x7f07ac079200>)

If I try to read a PIN from gmoccapy as gmoccapy.blockheigt like this:

Code:

hal_glib.GComponent("gmoccapy")["blockheight"]

I get an error like:

Code:

Traceback (most recent call last):
  File "./timer.py", line 123, in _periodic2
    print("gmoccapy = ", hal_glib.GComponent("gmoccapy")["blockheight"])
  File "/home/norbert/linuxcnc-org/lib/python/hal_glib.py", line 77, in __getitem__
    def __getitem__(self, k): return self.comp[k]
TypeError: string indices must be integers, not str

If I try a integer, I just get the corresponding letter of the component name.

Is there a way to read a hal pin from an component outside the own component?
A signal would also be OK, but first I will need to get the "component address" and all my test have failed till now.

Appreciate your help.

Norbert

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andypugh
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5 years 7 months ago #202695 by andypugh

Replied by andypugh on topic How to read hal pin from embedded panel from an other component

newbynobi wrote: I get True for gmoccapy, debug_panel, abs and False for motion.

The component name for motion is "motmod"

Code:

halcmd: show comp
Loaded HAL Components:
ID      Type  Name                                            PID   State
    72  User  halcmd96007                                     96007 ready
...
    20  RT    __servo-thread                                        ready
    19  RT    motmod                                                ready
...

Is there a way to read a hal pin from an component outside the own component?

Code:

import hal
...
v = hal.get_value("motion.program-line")

I don't know if the hal python interface is documented anywhere but here:
linuxcnc.org/docs/2.8/html/hal/halmodule.html

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5G-antry
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4 years 9 months ago #231473 by 5G-antry

Replied by 5G-antry on topic How to read hal pin from embedded panel from an other component

Hello,

Did you manage to read the values of PINs and/or Signals and use them in external software in "real time" (miliseconds range)?
I am currently developing kind of a digital twin of a cnc machine and I am struggeling with this topic.

Best Regards

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Grotius
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4 years 9 months ago #231625 by Grotius

Replied by Grotius on topic How to read hal pin from embedded panel from an other component

Hi,

Here is a c++ example.
1. It finds a component by name.
2. It can retrieve a value of a component item.
3. It shows how to retrieve the servo-time

Code:

double hal_interface::print_servo_thread_time(){

    /*
    if (halpr_find_comp_by_name("matrix") != 0) {
        std::cout << "matrix found!" << std::endl;
    }
    if (halpr_find_param_by_name("matrix.tmax") != 0) {
        std::cout << "matrix.time found!" << std::endl;
    }*/

    //! Get parameter value example
    /*
    hal_param_t *param;
    hal_type_t type;
    void *d_ptr;

    param = halpr_find_param_by_name("matrix.tmax");
    if (param) {
        type = param->type;
        d_ptr = SHMPTR(param->data_ptr);
        static char buf[15];
        snprintf(buf, 14, "%ld", (long)*((hal_s32_t *) d_ptr));

        std::cout<<"value:"<<buf<<std::endl;
    }*/

    //! Get pin value example
    /*
    if (halpr_find_pin_by_name("matrix.time") != 0) {
        std::cout << "matrix.time found!" << std::endl;
    } */

    hal_data_u *value;
    hal_type_t type;
    bool *con = nullptr;
    int r=hal_get_pin_value_by_name("matrix.mainfunction.time",&type,&value,con);
    if(r!=0){
        std::cout<<"error from /libhal/hal_interface function"<<std::endl;
    }
    // std::cout << "matrix.time function result:"<<ok<< std::endl;
    // std::cout << "matrix.time function result:"<<value->s<< std::endl;

    return value->s;
}

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Grotius
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4 years 9 months ago #231626 by Grotius

Replied by Grotius on topic How to read hal pin from embedded panel from an other component

For example c++:    //! Get pin value example
    if (halpr_find_pin_by_name("matrix.time") != 0) {
        std::cout << "matrix.time found!" << std::endl;
    }

github.com/LinuxCNC/linuxcnc/blob/a2f1fd...src/hal/halmodule.cc
Python line 991 :
# Get a Pin, Param or signal value
PyObject *get_value(PyObject *self, PyObject *args)

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