Tinit Routine - IBM 5280 Programmer's Manual

TINIT Routine
After execution, each routine returns a completion code in a data item you
code in your COBOL program as described later in this appendix.
Horizontal and Vertical TAB translations and Data Formatting (specified by
HTAB and VTAB in assembler language programs) are not supported.
However, you can use any feature which the communication access method
supports, even though you cannot specify them in the parameter lists
described later in this chapter. Instead, you specify the feature when you run
the communication preparation utilities. See the Communications
Configuration Utility described in the Communications Reference Manual for
a list of the features available and information on preparing your
communications environment for your program.
This routine is called to define a communications environment and initialize
the line. This must be the first routine called before any Communications
I/O. Any options specified in the parameter list will override the same
options you specify in the communications control record created by the IBM
5280 Communications Configuration Utility.
The format of the statement to call the TINIT routine is:
CALL "AVCLINIT" USING parameter-l buffer-2
parameter-l and buffer-2 are data-items you code as follows:
01 parameter-1
02 return-code PIC 9999.
02 record-length PIC 9999.
02 blocksize PIC 9999.
02 protocol PIC AAA.
02 record-format PIC AA.
02 type-1 PIC AA.
02 type-2 PIC AA.
01 buffer-2
PIC X(n).
buffer-2 is where you place the record to be sent, or where you want a record
to be received. When sending data under SNA, you should, if required, place
the log-on data in the first 80 bytes of this record.
The contents of the parameter-l record is as follows:
return-code - contains a code posted by the TINIT routine upon
completion. The return-codes and their meanings are explained in
Appendix H of the IBM 5280 Communications Reference Manual,
SC34-0247.
record length - Specify the length of the record to be read.
blocksiZe - Specify the maximum length of the block to be transmiiied.
Specify 0, if you want to use the blocksize specified in the
communications control record (CCR).
protocol- if system network architecture is used, specify SNA.
Otherwise, BSC is assumed.
record-format - for BSC only (this field is ignored for SNA). Specify
one of the following:
• FU, for fixed length unblocked
• VU, for variable length unblocked
FB, for fixed length blocked
A- 2 IBM 5280 COBOL Programmer's Guide