When adding mathematical transformations to Custom OID Polling with the MIB Browser or manually editing OIDEntry.cfg  follow the format below.

  • You can use addition, subtraction, multiplication, division, exponentiation, and parentheses.
  • The OID value is denoted by the symbol V. If this symbol is not present, it is automatically added to the beginning of the formula.
  • Supported functions: min(a,b), max(a,b), round(a)

Examples
  • *5 = Multiply result by 5
  • F = Convert value to Fahrenheit
  • C = Convert value to Celsius
  • round(-5 + max(V^2, F)/1.27) = more complex example

Also: do not put expression in quotes -- they are not recognized.
The transform is skipped only if the whole field is /, not just begins with it.