Envoy ACP/XF Application Programming Manual

System Procedure Call Specifics for EnvoyACP/XF

EnvoyACP/XF Application Programming Manual–132179

4-13

SETMODE Procedure

Condition Codes

Examples

In the following example, fnum is the number returned by the OPEN call that opened

the communications line, and in^buffer is the name of the integer array within the

application program into which EnvoyACP/XF places the received data. The read-

count of 102 specifies that the application program accepts an incoming frame

containing up to 100 bytes of data (remember that this count also includes the two-byte

MCW).

CALL READ (fnum,in^buffer,102);

The next example is the same as the preceding one except that the READ call includes

count^read, the name of an integer variable into which EnvoyACP/XF places a value

specifying how many bytes were actually deposited into the application buffer. If an I-

frame containing 75 bytes of data is received, count^read is set to 77 (remember that this

count also includes the 2-byte MCW). However, if the incoming frame is an

unnumbered command or response (such as a UA or a SABM), count^read is set to

CALL READ (fnum,in^buffer,102,count^read);

SETMODE Procedure

A call to the SETMODE procedure defines one or more line characteristics, such as the

line type (point-to-point switched, point-to-point nonswitched, or multipoint), the station

type (primary/supervisor or secondary/tributary), the maximum frame size, the number

of retries, and the timeout duration.

You also can call SETMODE to establish an extended address field.

If there are nowait requests incomplete when the application processes a SETMODE

call, the EnvoyACP/XF rejects the SETMODE request with CCL and a file-system error

code of 160 (request invalid for line state).

SETMODE requests that affect basic line characteristics, such as the electrical interface

being used, cause the EnvoyACP/XF line to reset and place all defined stations in the

disconnect state. The application process then must issue a CONTROL 13 to reenable

the link. The SETMODE function codes that reset the link are indicated by an asterisk in

Table 4-4

= (CCE) indicates that the READ[X] procedure was executed successfully.

= (CCL) indicates that an error occurred (call FILE_GETINFO_).

Note. SDLC does not support extended address fields.