The SuperMicro power supply PWS-341P-1H works in conjunction with the SuperMicro IPMI Tools, see their download page. Despite using the PMBus specifications not every manufacturer follows them exactly and some (especially SM) add additional features. You'll get the best results if you download their software, for their hardware.

The X9DAi motherboard uses a "JPI^I2C1 Power Supply SMBbus I²C Header", while the PWS-341P-1H power supply utilizes PMBus (Power Management Bus) over I2C, with SMBus as the underlying protocol, and includes a dedicated 5-pin connector for communication. If the power supply isn't listed on the motherboard's compatibility list you can't be certain that you can plug it into the motherboard, and subsequently run software that will access the hardware; and return the correct information.

Other people have had these problems, having a mismatch between the connections on the power supply and motherboard, as described here: "Terri Kennedy's web page", mentioned in the STH Forum -"i2c, smbus, pmbus, pulling my hair out.", or "How Do PMBus vs SMBus vs I2C Compare?" or LevelOneTechs - "Reading Supermicro PSU Info from Linux (SMBus)".

1.: Check that you can plug the power supply's PMBus communication cable into your motherboard:

2.: Download SuperMicro's utilities from the second link above.

3.: Check out the SMCIPMITool and its .PDF Manual:

pminfo: Use this command to display information on the health of the PMBus.

Usage: pminfo [<bus ID> <slave address>]

4.: Once you obtain the correct information, after ensuring that the hardware is compatible and connected correctly, you can approach your final part of your question:

"I am looking for a solution to programatically retrieve the PSU sensors values. Python or bash prefered but really any hacky solution will do. I can provide any log that would be relevant."

In the LevelOneTech Forum user "yucko" resorted to using curl to access the BMI:

"

use the redfish api to get this info, this gives json back:

curl -sS https://${BMC_HOST}/redfish/v1/Chassis/1/Power/ -k -u ${BMC_USER}:${BMC_PASS}

".