Parameters

Channel API

These functions are available for all channel types. Some channel types may have additional functions available, these are documented in the following sections.

chX.info() Provide a description of the channel type.

chX.ask(topic) Read the current value of a topic from the device.

chX.echo(topic, dt=0.001) Continuously read and print the value of a topic from the device every dt seconds. Throw an interrupt using Ctrl+C to stop.

chX.dump() Print all available topics for a given channel and their current values. Please consult the topics section for a more detailed description of available topics.

For example:

import ardi                 # import the ardi library
psu = ardi.autoconnect()    # connect to the first device found
ch1 = psu.channels['ch1']   # bind the first channel to the variable ch1
ch1.info()                  # print a description of ch1
ch1.dump()                  # print all available topics for ch1
ch1.ask('v_mon')            # read the voltage monitor of ch1

Topics

NOTE: This information is included as a reference. Reading these values via ask or echo is always safe. However, please do not attempt to modify these values, as doing so can cause permanent damage to the power supply and any connected hardware.

System

topic	type	units	description
`firmware`	str	–	firmware version
`hardware`	str	–	hardware version
`cpu_temp`	f32	°C	CPU temperature
`n_channels`	u8	–	number of channels
`n_callbacks`	u8	–	number of active callbacks
`state`	u8	–	state machine state
`uptime`	u32	ms	system uptime in ms (resets every ~49.7 days)
`cause_of_panic`	str	–	description of what caused the panic state

System State

The system state is a single byte that encodes the current state of the power supply. The state is encoded as follows:

value	state	description
0	STANDBY	high voltage is off
1	AUTOCAL	calibrating controller to connected loads
2	ARMED	high voltage is on, waiting on a trigger
3	ACTIVE	high voltage is on, outputs are active
4	PANIC	high voltage is off, problem detected

HV Rail

topic	type	units	description
`v_mon`	i16	V	rail voltage (from psu monitor)
`i_mon`	i16	μA	rail current (from psu monitor)

Unipolar Channels

topic	type	units	description
`state`	u8	–	state machine state
`pattern_dt`	u32	μs	voltage pattern update rate
`control_dt`	u32	μs	controller update rate
`v_pattern`	u16	V	programmed voltage pattern
`v_ref`	u16	V	instantaneous setpoint voltage
`v_mon`	u16	V	instantaneous measured voltage
`v_rail`	u16	V	instantaneous rail voltage
`v_err`	u16	V	voltage error
`kp`	f32	–	controller proportional gain
`ki`	f32	–	controller integral gain
`kd`	f32	–	controller derivative gain
`kf`	f32	–	controller filter gain
`u_max`	u8	–	charge PWM duty cycle limit
`u_min`	u8	–	drain PWM duty cycle limit
`e_min`	u16	–	error threshold for hold state
`p_out`	u8	–	controller output magnitude
`p_chg`	u8	–	charge PWM duty cycle
`p_drn`	u8	–	drain PWM duty cycle
`v_idle`	u16	V	idle voltage threshold
`p_idle`	u8	–	idle state drain duty cycle
`p_cal`	u8	–	calibration PWM duty cycle
`v_cal`	u16	V	calibration voltage target
`t_cal`	u32	μs	calibration time
`hasel_ok`	bool	–	short detection flag
`badness`	u32	–	short detection counter
`v_bad`	u16	V	short detection voltage threshold
`max_badness`	u32	–	short detection threshold

Bipolar Channels

topic	type	units	description
`state`	u8	–	state machine state
`pattern_dt`	u32	μs	voltage pattern update rate
`control_dt`	u32	μs	controller update rate
`v_pattern`	u16	V	programmed voltage pattern
`v_ref`	u16	V	instantaneous setpoint voltage
`v_mon_a`	u16	V	channel A measured voltage
`v_mon_b`	u16	V	channel B measured voltage
`v_mon`	u16	V	differential measured voltage
`v_rail`	u16	V	measured rail voltage
`v_err`	u16	V	voltage error
`kp`	f32	–	controller proportional gain
`ki`	f32	–	controller integral gain
`kd`	f32	–	controller derivative gain
`kf`	f32	–	controller filter gain
`u_max`	u8	–	charge PWM duty cycle limit
`u_min`	u8	–	drain PWM duty cycle limit
`e_min`	u16	–	error threshold for hold state
`gnd_A`	u8	–	channel A ground PWM duty cycle
`gnd_B`	u8	–	channel B ground PWM duty cycle
`p_out`	u8	–	controller output magnitude
`p_chg_a`	u8	–	channel A charge PWM duty cycle
`p_drn_a`	u8	–	channel A drain PWM duty cycle
`p_chg_b`	u8	–	channel B charge PWM duty cycle
`p_drn_b`	u8	–	channel B drain PWM duty cycle
`p_gnd`	u8	–	grounding PWM duty cycle
`v_idle`	u16	V	idle voltage threshold
`p_idle`	u8	–	idle state drain duty cycle
`p_cal`	u8	–	calibration PWM duty cycle
`v_cal`	u16	V	calibration voltage target
`t_cal`	u32	μs	calibration time
`hasel_ok`	bool	–	short detection flag
`badness`	u32	–	short detection counter
`v_bad`	u16	V	short detection voltage threshold
`max_badness`	u32	–	short detection threshold