APPC/MVS Host Command Environments

The CPICOMM environment enables you to invoke the SAA CPI Communications calls and the LU62 and APPCMVS environments enable you to invoke APPC/MVS calls. You can write transaction programs in the REXX language, using the LU62, CPICOMM, or APPCMVS host command environments, to issue APPC calls to a partner transaction program. The CPICOMM host command environment allows transaction programs written in the REXX language to be ported across SAA environments. The LU62 host command environment allows you to use specific features of MVS™ in conversations with transaction programs on other systems. APPCMVS allows you to access APPC/MVS callable services related to server facilities and for the testing of transaction programs. Each of these host command environments enable REXX programs to communicate with other programs on the same MVS system, different MVS systems, or different operating systems in an SNA network.

The following APPC/MVS calls are supported under the APPCMVS host command environment:

ATBCUC1 (Cleanup_TP(Unauthorized))
ATBGTE2 (Get_Event)
ATBPOR2 (Post_on_Receipt)
ATBQAQ2 (Query_Allocate_Query)
ATBRAL2 (Receive_Allocate)
ATBRFA2 (Register_for_Allocate)
ATBRJC2 (Reject_Conversation)
ATBSAQ2 (Set_Allocate_Queue_Attributes)
ATBSCA2 (Set_Conversation_Accounting_Information)
ATBSTE2 (Set_Event_Notification)
ATBTEA1 (Accept_Test)
ATBTER1 (Register_Test)
ATBTEU1 (Unregister_Test)
ATBURA2 (Unregister_for_Allocates)
ATBVERS (MVS_Version_Check)

The following SAA CPI Communications calls are supported under the CPICOMM host command environment:

CMACCP (Accept_Conversation)
CMALLC (Allocate)
CMCFM (Confirm)
CMCFMD (Confirmed)
CMDEAL (Deallocate)
CMECS (Extract_Conversation_State)
CMECT (Extract_Conversation_Type)
CMEMN (Extract_Mode_Name)
CMEPLN (Extract_Partner_LU_Name)
CMESL (Extract_Sync_Level)
CMFLUS (Flush)
CMINIT (Initialize_Conversation)
CMPTR (Prepare_To_Receive)
CMRCV (Receive)
CMRTS (Request_To_Send)
CMSCT (Set_Conversation_Type)
CMSDT (Set_Deallocate_Type)
CMSED (Set_Error_Direction)
CMSEND (Send_Data)
CMSERR (Send_Error)
CMSF (Set_Fill)
CMSLD (Set_Log_Data)
CMSMN (Set_Mode_Name)
CMSPLN (Set_Partner_LU_Name)
CMSPTR (Set_Prepare_To_Receive_Type)
CMSRC (Set_Return_Control)
CMSRT (Set_Receive_Type)
CMSSL (Set_Sync_Level)
CMSST (Set_Send_Type)
CMSTPN (Set_TP_Name)
CMTRTS (Test_Request_To_Send_Received)

The SAA CPI Communications calls are described in SAA Common Programming Interface Communications Reference.

The following APPC/MVS calls are supported under the LU62 host command environment:

ATBALC2 (Allocate)
ATBALLC (Allocate)
ATBCFM (Confirm)
ATBCFMD (Confirmed)
ATBDEAL (Deallocate)
ATBFLUS (Flush)
ATBGETA (Get_Attributes)
ATBGETC (Get_Conversation)
ATBGETP (Get_TP_Properties)
ATBGETT (Get_Type)
ATBGTA2 (Get_Attribute)
ATBPTR (Prepare_To_Receive)
ATBRCVI (Receive_Immediate)
ATBRCVW (Receive_And_Wait)
ATBRTS (Request_To_Send)
ATBSEND (Send_Data)
ATBSERR (Send_Error)

Note: The numeric suffix within the service name indicates the MVS release in which the service was introduced and thereby also available in all subsequent releases, as follows:

none: MVS SP4.2 service. For example, ATBGETA
1: MVS SP4.2.2 service. For example, ATBTEA1
2: MVS SP4.3 service. For example, ATBALC2

Therefore, your z/OS base control program (BCP) must be at least at the indicated level to take advantage of these services.

The parameters for these services and the requirements for using them in APPC/MVS transaction programs are described in z/OS MVS Programming: Writing Transaction Programs for APPC/MVS.