IRXEXCOM Fetch Invocation Help

[Selig Tessler]

I am writing a z/OS Assembler routine which is called by a REXX EXEC which creates several stem variables (the REXX EXEC creates the stem variables). The Assembler routine calls IRXEXCOM to fetch the stem variables created by the REXX EXEC. Unfortunately, I am getting rc=32 (invalid parameter list).

This is the parameter list:
EXCMPLST DS 0D IRXEXCOM PARM LIST
EXCMEYEC DS CL8 'IRXEXCOM' EYECATCHER
EXCMZER1 DS F SET TO ZERO
EXCMZER2 DS F SET TO ZERO
EXCMSHVB DS CL(SHVBLEN) REXX SHARED VARIABLE REQUEST BLK
EXCMENVB DS A PTR TO ENVIRONMENT BLOCK
EXCMRTCD DS F RETURN CODE

The high-order byte of EXCMRTCD is set to x'80'.

Can anyone tell me what I am doing wrong? It looks to me that I am following the instructions in the TSO/E REXX Reference manual.

If you don't see anything wrong, can you please send me an example of an IRXEXCOM fetch invocation (in any language)?

Thank you very much,
Selig Tessler

[Willy Jensen]

Extract from assembly below, this is an expansion of macro call:
RxVget name='testvar1',data=(vardata,l'vardata)
You might be interested in my collection of REXX interface macros, see REXXMACS at https://harders-jensen.com/. There are macros for GET, STEMGET, PUT, STEMPUT, NEXT, SAY and more. The doc is a bit lacking, but drop me a note if you need more info.

mvi ZRX_ShVbFunc,C'F' fetch
*setup for data
laey R14,VARDATA
laey R15,L'VARDATA
stm r14,r15,ZRX_ShVbVba
st r15,ZRX_ShVbFbl
*setup for name
laey R14,=c'TESTVAR1'
la r15,8
stm r14,r15,ZRX_ShVbVna
*setup for call
mvc ZRX_ShVUser,ZRX_ShVbVnl for 'next'
l r15,zrx_coma address of module irxexcom
l r0,zrx_envba
la r1,ZRX_Comblk
Basr r14,r15
l r0,ZRX_ShVbVbl
l r1,ZRX_ShVbVnl

ZRX_ShVb ds 0d
ZRX_ShVbNext ds a -> next ShVb
ZRX_ShVUser ds f Used by 'next' function
ZRX_ShVCode ds 0c F=Fetch, S=Set (put)
ZRX_ShVbFunc ds c F=Fetch, S=Set (put)
ZRX_ShVRet ds 0x Return code area
ZRX_ShVbRc ds x Return code area
ZRX_last equ x'02' last var transferred flag
ZRX_eof equ x'02' last var transferred flag
ZRX_trunc equ x'04' 'truncated' flag
ds h Reserved
ZRX_ShVbFbl ds a Length of fetch buffer
ZRX_ShVbVna ds a -> variable name
ZRX_ShVbVnl ds a length of variable name
ZRX_ShVbVba ds a -> value buffer
ZRX_ShVbVbl ds a Length of fetched value