SNAX/APN Application Programming Manual

The CRT Interface

SNAX/APN Application Programming Manual—420111-001

2-9

Functions Available With the CRT Protocol

This subsection describes the functions available when using the CRT protocol to

communicate with 3270-type devices (terminals and printers). The following table lists

the functions and the procedure calls that you use to perform the functions:

Each of these functions is described in this subsection.

In the syntax diagrams used in this subsection, filenum is a number identifying an

open file, which in turn identifies the device to receive the procedure call. For more

information on the syntax of the SETMODE, SETPARAM, and CONTROL procedure

calls, see the Guardian Procedure Calls Reference Manual.

Setting Transfer Mode (SETMODE Function 8)

SETMODE function 8 is used to set transfer mode. “Transfer mode” refers to the way

you transfer data. It can be block mode (page mode) or conversational (line-at-a-time)

mode. The CRT interface supports block-mode communication. However, an

application can use the SETMODE procedure to switch between block mode and

conversational mode, as follows:

param1

0 Enables conversational mode (ITI)

1 Enables block mode (CRT)

last-params

allows you to view the most recent option setting. Because the option can also be

set using SCF or SPI, the returned value indicates the setting before this call takes

effect.

Function Procedure Call

Setting transfer mode SETMODE function 8

BREAK key-related functions:

Setting BREAK key ownership SETMODE function 11

Setting and fetching BREAK parameters SETPARAM function 3

Setting terminal access mode and file access type SETMODE function 12

Obtaining SNA sense codes SETMODE function 53

Placing a session in the between brackets (BETB) state SETMODE function 112

Setting CDI options SETMODE function 163

Waiting for the LU to start CONTROL operation 11

CALL SETMODE ( filenum , 8 , param1 ) , ,

[ last-params ] ) ;