The next sections describe fields in the parameter list that can be reset within
DFHZNEP. See also “Coding for the 3270 ‘unavailable printer’ condition” on page
506, which describes the use of the flags in the “unavailable printer return code”
field, and “Using the node error program with XRF or persistent sessions” on page
510, which describes how the flags in the XRF part of the parameter list can be
manipulated.
The user option bytes (TWAOPTL)
TWAOPTL contains the user option bytes TWAOPT1, TWAOPT2, and TWAOPT3,
each of which contains action flags. On entry to DFHZNEP, these flags represent
the default actions previously set by DFHZNAC. They can be reset by DFHZNEP.
TWAOPT1
User option byte 1. TWAOPT1 contains flags which are principally debugging
aids. The first five flags cause DFHZNAC to write the desired information to the
CSNE log if the appropriate bit is set. Setting the sixth flag (TWAODNTA) on
**********************************************************************
** Additional system parameters **
**Except for TWAPNETN, TWAPNTID, TWAUPRRC these fields are READ ONLY**
**********************************************************************
TWASYSPM DS 0XL68
TWATCTA DS AL4 Address of TCTTE being processed
TWARPL DS AL4 Address of VTAM RPL
TWATIOAA DS AL4 Address of data portion of TIOA
TWATIOAL DS H Length of data portion of TIOA
TWACOMML DS H Length of commarea data for TCTTE
TWACOMMA DS CL4 Address of commarea data for TCTTE
TWATECIA DS AL4 Address of TCTTE user area
TWATECIL DS H Length of TCTTE user area
TWAPPNTN DS CL8 Primary 3270 printer netname
TWAPPTID DS CL4 Primary 3270 printer termid
TWAPPELG DS X Primary printer eligible indicator
TWAPPELY EQU X’01’ Primary printer is eligible flag
TWASPNTN DS CL8 Secondary 3270 printer netname
TWASPTID DS CL4 Secondary 3270 printer termid
TWASPELG DS X Secondary printer eligible indicator
TWASPELY EQU X’01’ Secondary printer is eligible flag
TWAPNETN DS CL8 Selected 3270 printer netname
TWAPNTID DS CL4 Selected 3270 printer termid
TWAUPRRC DS B Unavailable Printer return code
TWAUPRNP EQU X’00’ No printer selected
TWAUPRPS EQU X’01’ Printer selected
TWAUPRDD EQU X’FF’ Data disposal complete
TWAUPRPE EQU X’FE’ Error on Put request
TWAERRF1 DS B Error flag byte 1
TWALXS EQU X’80’ Logon crossed simlogon
DS XL2 Reserved
**********************************************************************
** XRF parameters **
** XRF recovery notification data **
** DFHZNEP can change these default actions **
**********************************************************************
TWAXRNOT DS X Recovery notification options
TWAXRNON EQU X’80’ Recov notification = none
TWAXRMSG EQU X’40’ Recov notification = message
TWAXRTRN EQU X’20’ Recov notification = transact.
DS XL3 Reserved
TWAXMSTN DS CL8 Recovery mapset name
TWAXMAPN DS CL8 Recovery map name
TWAXTRAN DS CL4 Recovery transaction ID
*
Figure 33. The DFHZNAC/DFHZNEP communication area (part 3)
Chapter 9. Writing a node error program 491