Appendix E. PU Finite-State Machines

The PU finite-state machines returned by the gfsm verb structure fsm_pu holds the current state of some of the finite-state machines used in the PU.

The fsm_lu is a structure with the following members:

hex

sess

SSCP-PU session status

hex

im_rq_s

Immediate request mode send

sess is used to record the secondary SSCP-PU half-session state. The following values are defined:

P01_CPPU 

Reset.

P02_CPPU 

An ACTPU has been received but not responded to.

P03_CPPU 

An ACTPU has been positively responded to.

P04_CPPU 

A DACTPU (not SON) has been received but not

 

responded to.

P05_CPPU 

A DACTPU (SON) has been received but not

 

responded to.

im_rq_s is used to enforce the immediate request mode protocol. The following states are maintained:

P01_IMRQ 

Not in chain, no definite response required.

P02_IMRQ 

Definite response required, CANCEL not sent.

P03_IMRQ 

In chain.

P04_IMRQ 

Response received while in chain.

P05_IMRQ 

Definite response to CANCEL required.