Py-Lab-HAL is a multi-platform Python library for Lab Test Equipment Control and Automation. It has been run and tested under Windows, Linux, and Mac.
We support some common and uncommon lab test equipment:
Py-Lab-HAL also supports multiple equipment interfaces:
py-lab-hal is on PyPI, and it's installable via pip.
pip install py-lab-halFor linux users, you will have to run an extra step:
echo "SUBSYSTEM==\"usb\", MODE=\"0666\", GROUP=\"usbusers\"" | sudo tee -a /etc/udev/rules.d/99-usbusers.rulesto configure your USB device access or you won't be able to see instruments over an USB connection. You might have to restart the computer after entering the command.
Let's get our basic imports out of the way:
from py_lab_hal import builder
from py_lab_hal.cominterface import cominterfaceThe builder helps us build the instrument while cominterface defines the
communication interface in which the host/test computer will use to talk to the
test equipment.
Creating the builder is a simple one-liner:
build = builder.PyLabHALBuilder()Since Py-Lab-HAL is supporting various interfaces, there are quite a lot of parameters to set up across each interface. For details, check out the source.
To see what is connected to your system and their resource data, you can use our built-in utility in a terminal:
python3 -m py_lab_hal.scanThis will scan and list out all the visa_resources available to your system.
An USB or VXI-11 connection is straight-forward,
just fill in the visa_resource you need:
build.connection_config = cominterface.ConnectConfig(
visa_resource='USB0::10893::769::MY59006118::0::INSTR',
)For Socket connections, you will need to know the
socket_host and socket_port of your instrument. This will be filled into
an addition config, NetworkConfig, which you can define separately, or
in-line as we have done here:
build.connection_config = cominterface.ConnectConfig(
network=cominterface.NetworkConfig(
host='192.168.11.11',
port=5025,
),
)Setting up serial connection is the most involved as it contains
the most parameters. As in socket, you will need to fill out an addition config,
SerialConfig. If you are using all default values, then you can just pass in
SerialConfig as is, if not, you will need to set it up. The parameters and
their defaults are as follows:
cominterface.SerialConfig(baud_rate = 9600)cominterface.SerialConfig(data_bits = 8)cominterface.StopBits.ONE
cominterface.StopBits.ONE
cominterface.StopBits.ONE_POINT_FIVE
cominterface.StopBits.TWOcominterface.SerialConfig(stop_bits = cominterface.StopBits.ONE)
* Parity
* Default = 'N' or `cominterface.Parity.NONE`
* Select from:
```python
cominterface.Parity.EVEN
cominterface.Parity.NONE
cominterface.Parity.SPACE
cominterface.Parity.MARK
cominterface.Parity.ODD
#Usage
cominterface.SerialConfig(parity = cominterface.Parity.NONE)
cominterface.ControlFlow.DTR_DSR
cominterface.ControlFlow.RST_CTS
cominterface.ControlFlow.NONE
cominterface.ControlFlow.XON_XOFFcominterface.SerialConfig(flow_control = cominterface.ControlFlow.RST_CTS)
A small example of overriding some of the default values when setting up
`SerialConfig`:
```python
build.connection_config = cominterface.ConnectConfig(
visa_resource='ASRL/dev/ttyUSB0::INSTR',
serial_config=cominterface.SerialConfig(
baud_rate=115200,
flow_control=cominterface.ControlFlow.RST_CTS,
),
)Now that the builder has been instantiated and cominterface setup, it is time to build and instantiate the actual instrument!
But first we need to make sure our initalization call to the instrument is set up correctly:
The instrument configuration and their defaults are listed below:
build.instrument_config.reset = True
build.instrument_config.clear = True
build.instrument_config.idn = True
build.instrument_config.auto_init = Truereset, clear, and idn are standard VISA SCPI commands, while auto_init
is a Py-Lab-HAL command. The first 3 commands and their SCPI equivalents are as
follows:
reset = *RSTclear = *CLRidn = *IDN?auto_init determines whether to open a connection to the instrument after
builder instantiates the object. If you select false, you will have to issue a
separate call to open a connection to the instrument.
Note: reset, clear, and idn only applies to VISA SCPI instruments. For non-VISA instruments, all 3 of these flags must be set to False or you will get an error with the instrument. A few examples of a non-VISA instrument would be: robot arm, panel light, temp chamber, and generic USB relay.
To finish building the instrument, we will invoke the build_instrument
function:
build.build_instrument(builder.FOLDER_NAME.MODULE_NAME)Where:
FOLDER_NAME = The type of equipment, e.g., DMM, DC Power Supply, etc.MODULE_NAME = The module or model name of the instrument, e.g., Keysight,
Tektronix, Lecroy, etc. The MODULE_NAME follows the convention ofMAKER_MODEL, for example: KEYSIGHT_N6705C in all caps.Usage:
dcpsu = build.build_instrument(builder.DCPowerSupply.KEYSIGHT_N6705C)
dmm = build.build_instrument(builder.DMM.AGILENT_34465A)For details on putting it all together, see the example below and our demo folder for more examples.
import time
from py_lab_hal import builder
from py_lab_hal.cominterface import cominterface
build = builder.PyLabHALBuilder()
build.connection_config = cominterface.ConnectConfig(
visa_resource='USB0::10893::769::MY59006118::0::INSTR',
)
dmm = build.build_instrument(builder.DMM.AGILENT_34465A)
build.connection_config = cominterface.ConnectConfig(
visa_resource='ASRL/dev/ttyUSB0::INSTR',
serial_config=cominterface.SerialConfig()
)
dcpsu = build.build_instrument(builder.DCPowerSupply.GWIN_PST3202)
try:
dcpsu.set_output(1, 5, 1)
dcpsu.enable_output(1, True)
print('output 5 V')
time.sleep(1)
for i in range(5):
print(dmm.read())
dcpsu.set_output(1, 6, 1)
dcpsu.enable_output(1, True)
print('output 6 V')
time.sleep(1)
for i in range(5):
print(dmm.read())
finally:
dmm.close()
dcpsu.close()This is not an official Google product.