Read variable with Python

[albova]

hi to all,

the problem:

in axis there is a signal " axis.0.joint-pos-fb" that it gives back the position of axis 0 (x in my case)

how I make to read the variable from a program python?

thanks

Alessandro

[Nolive]

Hello

I have exactly the same question.
Did you find out how to proceed?
I will look at the emc2 and axis code to try to find the answer...

Thanks

Olivier

[chester88]

In your python code include python-HAL glue code.
your python program will create a HAL pin and then you connect the signal you want to read to it. (This will not be realtime though)
see:
Creating Userspace Python Components with the 'hal' module

By the way that signal name that was quoted is NOT from the AXIS display program.

see here:
EMC2's interface to HAL

Chris M

[nkp]

Originally Posted by chester88 In your python code include python-HAL glue code.

Hello!
Could you give me a small example.
I want to get into Python code the value motion.program-line.
(Userspace Python Components know how to create.)
Sorry for my English.

[chester88]

there is an example in the manual that i gave a link to.
you would need to change the pin type to s32 instead of float, as the pin you wish to connect to is an s32 pin.

then you would need to connect the pin you wish to read to the pin you made in the python program. You do that in a HAL file eg :

net signal_name motion.program-line passthrough.in

(using the example python program in the manual called passthrough)

[chester88]

#!/usr/bin/python
import hal, time
h = hal.component("passthrough")
h.newpin("in", hal.HAL_S32, hal.HAL_IN)
h.newpin("out", hal.HAL_S32, hal.HAL_OUT)
h.ready()
try:
while 1:
time.sleep(1)
h['out'] = h['in']
print h['in']
except KeyboardInterrupt:
raise SystemExit



try this version of passthrough...

[nkp]

Thanks for the quick reply!
But the question is slightly different. Here is my component pult.py :
[code]

#!/usr/bin/python

import hal, time , serial
h = hal.component("pult")
h.newpin("out", hal.HAL_BIT, hal.HAL_OUT)
h.newpin("a", hal.HAL_BIT, hal.HAL_OUT)
h.newpin("b", hal.HAL_BIT, hal.HAL_OUT)
h.newpin("c", hal.HAL_BIT, hal.HAL_OUT)

h.newpin("numberin", hal.HAL_S32, hal.HAL_IN)
h.newpin("numberout", hal.HAL_S32, hal.HAL_OUT)


h.ready()
h['a'] = False
h['b'] = False
h['c'] = False
h['out'] = False


try:
    while 1:
		time.sleep(1)
		ser = serial.Serial('/dev/ttyS0', 115200, timeout=1)	
		x = ser.read()
		if x == '2' :
			h['out'] = True
		else :
			h['out'] = False
		if x == '3' :
			h['a'] = True
			h['b'] = False
		if x == '4' :
			h['b'] = True
			h['a'] = False
		if x == '5' :
			h['c'] = True
		ser.close()
		h['numberout'] = h['numberin']
		n=h['numberout']
except KeyboardInterrupt:
    raise SystemExit

In the hal file:

loadusr  -Wn pult python  pult.py
net numb motion.program-line  pult.numberin

Now we are writing a new Python script:

#!/usr/bin/python
bla... bla...bla..
x=n

A variable "n" - from pult.py (n = h ['numberout'])
I have tried so:

#!/usr/bin/python
import pult
x=n
print n

The result of an error-

>>> import pult
HAL: ERROR: duplicate component name 'pult'
Traceback (most recent call last):
  File "", line 1, in 
  File "pult.py", line 4, in 
    h = hal.component("pult")
hal.error: Invalid argument
>>> x=n
Traceback (most recent call last):
  File "", line 1, in 
NameError: name 'n' is not defined
>>> print n
Traceback (most recent call last):
  File "", line 1, in 
NameError: name 'n' is not defined
>>>

The question is, how to use a value of "n" in any script?

[nkp]

They here thus far prompted this method:

from subprocess import Popen, PIPE
a= Popen('halcmd getp minmax.0.max ', shell=True, stdout=PIPE).stdout.read()
x=int(a)
print x

In the hal file:

loadrt conv_s32_float 
addf conv-s32-float.0 servo-thread
net numb motion.program-line conv-s32-float.0.in
loadrt minmax 
addf minmax.0 servo-thread
net numb1 conv-s32-float.0.out   minmax.0.in