The HAL Python module

This documentation describes the hal python module, which provides a Python API for creating and accessing HAL pins and signals.

1. Basic usage

#!/usr/bin/env python3
import hal, time
h = hal.component("passthrough")
h.newpin("in", hal.HAL_FLOAT, hal.HAL_IN)
h.newpin("out", hal.HAL_FLOAT, hal.HAL_OUT)
h.ready()

2. Functions

component: +
The component itself is created by a call to the constructor hal.component. The arguments are the HAL component name and (optionally) the prefix used for pin and parameter names. If the prefix is not specified, the component name is used.
.Example

h = hal.component("passthrough")

newpin: +
Create new pin.
Arguments: pin name suffix, pin type, and pin direction. For parameters, the arguments are: parameter name suffix, parameter type, and parameter direction.
.Example:

h.newpin("in", hal.HAL_FLOAT, hal.HAL_IN)

ready: Tells the HAL system the component is initialized. Locks out adding pins.
unready: Allows a component to add pins after ready() has been called. One should call ready() on the component after.
component_exists: Does the specified component exist at this time.

Example

hal.component_exists("testpanel")

component_is_ready: Is the specified component ready at this time.

Example

hal.component_is_ready("testpanel")

get_msg_level: Get the current Realtime msg level.
set_msg_level: Set the current Realtime msg level. used for debugging information.
connect: Connect a pin to a signal.

Example

hal.connect("pinname","signal_name")

disconnect: Disconnect a pin from a signal.

Example

hal.disconnect("pinname")

get_value: Read a pin, param, or signal directly.

Example

value = hal.get_value("iocontrol.0.emc-enable-in")

get_info_pins(): Returns a list of dicts of all system pins.

listOfDicts = hal.get_info_pins()
pinName1 = listOfDicts[0].get('NAME')
pinValue1 = listOfDicts[0].get('VALUE')
pinType1 = listOfDicts[0].get('TYPE')
pinDirection1 = listOfDicts[0].get('DIRECTION')

get_info_signals(): Returns a list of dicts of all system signals.

listOfDicts = hal.get_info_signals()
signalName1 = listOfDicts[0].get('NAME')
signalValue1 = listOfDicts[0].get('VALUE')
driverPin1 = listOfDicts[0].get('DRIVER')

get_info_params(): Returns a list of dicts of all system parameters.

listOfDicts = hal.get_info_params()
paramName1 = listOfDicts[0].get('NAME')
paramValue1 = listOfDicts[0].get('VALUE')
paramDirection1 = listOfDicts[0].get('DIRECTION')

new_sig: Create a new signal of the type specified.

Example

hal.new_sig("signalname",hal.HAL_BIT)

pin_has_writer: Does the specified pin have a driving pin connected.
Returns True or False.

h.in.pin_has_writer()

get_name: Get the HAL object name.
Return a string.

h.in.get_name()

get_type: Get the HAL object’s type.
Returns an integer.

h.in.get_type()

get_dir: Get the HAL object direction type.
Returns an integer.

h.in.get_dir()

get: Get the HAL object value.

h.in.get()

set: Set the HAL object value.

h.out.set(10)

is_pin: Is the object a pin or parameter?
Returns True or False.

h.in.is_pin()

sampler_base: TODO
stream_base: TODO
stream: TODO
set_p: Set a pin value of any pin in the HAL system.

Example

hal.set_p("pinname","10")

set_s: Set the value of any unconnected signal in the HAL system.

Example

hal.set_s("signalname","10")