Supermicro IPMI SNMP voltage value

Tring to monitor the BMC IPMI on SuperMicro X11SSZ-TLN4F


Nagios1:/etc/mrtg# snmpwalk -c public -v 2c 10.20.1.39 1.3.6.1.4.1.21317.1.3.1 | grep ".48 "
SNMPv2-SMI::enterprises.21317.1.3.1.1.48 = INTEGER: 48
SNMPv2-SMI::enterprises.21317.1.3.1.2.48 = INTEGER: 191
SNMPv2-SMI::enterprises.21317.1.3.1.3.48 = INTEGER: 1
SNMPv2-SMI::enterprises.21317.1.3.1.4.48 = INTEGER: 1
SNMPv2-SMI::enterprises.21317.1.3.1.5.48 = INTEGER: 166
SNMPv2-SMI::enterprises.21317.1.3.1.6.48 = INTEGER: 158
SNMPv2-SMI::enterprises.21317.1.3.1.7.48 = INTEGER: 156
SNMPv2-SMI::enterprises.21317.1.3.1.8.48 = INTEGER: 200
SNMPv2-SMI::enterprises.21317.1.3.1.9.48 = INTEGER: 205
SNMPv2-SMI::enterprises.21317.1.3.1.10.48 = INTEGER: 207
SNMPv2-SMI::enterprises.21317.1.3.1.11.48 = INTEGER: 2580
SNMPv2-SMI::enterprises.21317.1.3.1.12.48 = INTEGER: 2580
SNMPv2-SMI::enterprises.21317.1.3.1.13.48 = STRING: "12V "

The "SNMPv2-SMI::enterprises.21317.1.3.1.2.48 = INTEGER: 191" is the reading value for the 12V power.
BMC web interface is saying the value is "12.384 Volts"

So how is the 191 translated into 12.384 ??

 

191 * 0.064 maybe?

 

yes that also what i got, but it it only close to what the webinterface is saying, more correct value is 0.0641

but how and where does this value come from and it is differen for each volt sensor.