Programmable power supply

This page documents the config keys are various other info needed to write a libsigrok frontend for controlling programmable power supplies.

TODO

• Some way to specify fixed values for voltage and current, for devices that have one or more of these fixed in some channels. Two options:
  • A boolean key _FIXED, per channel
  • A _MIN corresponding to _MAX: When set to the same as _MAX, denotes a fixed setting for that channel. This would also allow negative values, for e.g. a range -5V - 5V
• Over temperature protection: need some examples of whether this is ever something that is gettable/settable, or is only ever a hardware feature.

Notes

It's not unusual for different channels on a device to have different voltage or current limits. Therefore, channels will generally be in a probe group which allows setting these limits.

After setting SR_CONF_CHANNEL_OUTPUT, the limits of these channels may change, and the limits should be queried again.

Config keys

A libsigrok driver for a programmable power supply implements all or some subset of the following config keys.

SR_CONF_POWER_SUPPLY

Denotes a device that provides power output via one or more output channels, typically with voltage and current set via the sigrok driver.

SR_CONF_OUTPUT_VOLTAGE

• double, representing voltage.
• get: The current output voltage. This may not be the same as what was set -- the output may be disabled, or can change depending on the load.
• set: NA
• list: NA

SR_CONF_OUTPUT_VOLTAGE_MAX

• double, representing voltage.
• get: The previously set maximum output voltage, or device default.
• set: Maximum output voltage.
• list: Supported voltage range as (low, high, step).

SR_CONF_OUTPUT_CURRENT

• double, representing current.
• get: The actual output current. This may not be the same as what was set -- the output may be disabled, or can change depending on the load.
• set: NA
• list: NA

SR_CONF_OUTPUT_CURRENT_MAX

• double, representing current.
• get: The previously set maximum output current, or device default.
• set: Maximum output current.
• list: Supported current range as (low, high, step).

SR_CONF_OUTPUT_ENABLED

• boolean
• get: actual state of output
• set: turn output on or off

If a channel/probe group cannot be enabled or disabled separately from other channels, setting this key will return SR_ERR_NO. The set should then instead be tried with a NULL probe group, for devices that have only a global setting for this.

SR_CONF_OUTPUT_CHANNEL

If available, this key is used to set the channel output to independent (the default), series, or parallel.

TODO enumeration

SR_CONF_OVER_VOLTAGE_PROTECTION

• boolean
• get: current state of OVP
• set: turn OVP on or off

SR_CONF_OVER_CURRENT_PROTECTION

• boolean
• get: current state of OCP
• set: turn OCP on or off