Example: An intersystem communications function file using DDS

This example contains data description specifications (DDS) for transmitting data between the IBM i platform and a remote system or device.

The following keywords are important in the example:

Figure 1. ICF file
|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
00010A*
00020A*  SAMPLE ICF FILE
00030A*
00040A  01                             (3)  EOS
00050A                                 (2)  RCVTRNRND(01 'TRNRND INDICATION')
00060A                                 (2)  RCVDETACH(02 'DETACH RECEIVED')
00070A                                 (2)  RCVCONFIRM(03 'CONFIRM REQUEST')
00080A                                 (2)  RCVFAIL(04 'FAIL RECEIVED')
00090A
00100A          R CATCHALL
00110A            FLD1         132A
00120A*
00130A          R SNDEVOKE                  EVOKE(&LIBNME/&PGMNME);
00140A     (1)                              SYNLVL(*CONFIRM) SECURITY(2 PASSWRD)
00150A     (1)                              CONFIRM
00160A            PGMNME        10A  P
00170A            LIBNME        10A  P
00180A            PASSWRD        8A  P
00190A*
00200A          R HEADER                    RECID(1 'H')
     A
|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
00210A  09                                  CONFIRM
00220A            ID             1A
00230A        (4) PART#         12A
00240A            UNTCST         6S 2
00250A            QTYONORDR      9B 0
00260A            TOTAL          9B 0
00270A*
00280A          R DETAIL                    RECID(1 'D') RECID(1 'E')
00290A  09                                  CONFIRM
00300A            ID             1A
00310A        (4) LOC            6A
00320A            QTY            9B 0
00330A*
00340A          R COMMANDS
00350A  05                              (5) FALL
00360A  06                              (5) ALWWRT
00370A  07                              (5) DETACH
00380A  08                              (5) RQSWRT
00390A  09                              (5) CONFIRM
00400A  10                              (5) RSPCONFIRM
     A

Legend:

(1)
The record format SNDEVOKE causes the program specified in the field PGMNME and the library specified in the field LIBNME to be started on the remote system. It also establishes a synchronization level of *CONFIRM for the transaction and passes the data in the field PASSWRD as security information. The CONFIRM keyword requests that the remote system confirm the start of the program.
(2)
If the remote program performs any of the following actions:
  • Requests to end sending data
  • Requests to end the transaction
  • Requests to confirm receiving the data
  • Sends a FAIL
This sets on one of the following response indicators:
  • 01 (the RCVTRNRND keyword)
  • 02 (the RCVDETACH keyword)
  • 03 (the RCVCONFIRM keyword)
  • 04 (the RCVFAIL keyword)
(3)
The EOS keyword causes the session to end if indicator 01 is on and the program issues an output operation.
(4)
The system sends and receives data in the form of header records (record format HEADER) and detail records (record format DETAIL). If your program is sending, option indicator 09 can be set on, which enables the CONFIRM keyword to request the remote system to confirm receiving the data.

When receiving data, the record selection processing (RECID keyword) determines which record is received. If an H is in position 1, record format HEADER is selected. If a D or an E is in position 1, record format DETAIL is selected. If anything else is in position 1 (unexpected record format, application error, or indicators with no data, RCVDETACH, RCVFAIL, and so on), record format CATCHALL is selected.

(5)
Record format, COMMANDS, is used to request the following communications functions:
  • If indicator 05 is on, the FAIL function is performed.
  • If indicator 06 is on, the ALWWRT function is performed.
  • If indicator 07 is on, the DETACH function is performed.
  • If indicator 08 is on, the RQSWRT function is performed.
  • If indicator 09 is on, the CONFIRM function is performed.
  • If indicator 10 is on, the RSPCONFIRM function is performed.