rdisp/shutdown/trigger_timeout is a SAP Parameter attribute which is used to control Max. time to read the shutdown trigger inside ABAP and kernel information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
This parameter defines how long the kernel shutdown waits for the
shutdown trigger to be read by Auto ABAP.
The value 0 means that a timeout is not triggered when waiting.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.