AM3270/TR3271 Reference Manual

Details of the CRT Protocol

AM3270 Subdevice Protocols

086705 Tandem Computers Incorporated 4–15

For a more detailed discussion of sense and status bytes (which are displayed by using

the SCF command STATUS SU), including a table listing sense/status bytes, refer to

the SCF Reference Manual for AM3270 and TR3271.

Example of Use

An application may pass information back and forth between subdevices on an

AM3270 line and a TR3271 line. For example, it may be a function of an application

program to monitor physical device status and sense messages from the AM3270

subdevices while passing these messages to the TR3271 side. Furthermore, if a status

condition arises from a subdevice, it may be a function of the application program to

indicate that operator intervention is required by sending a message that informs

someone to take action.

SETMODE 54 Operation SETMODE 54 returns the control unit and device designations that are assigned to a

subdevice. The subdevice number (SDN), used internally by AM3270, and the

standard 3270 addresses are returned.

SETMODE 54 is useful for applications requiring use of the IBM COPY command in a

3270 buffer stream. The COPY command is issued to terminals or printers. It is

especially useful for printers in that the command instructs the controller to copy a

screen from a terminal to a printer (or to another terminal) that gets the COPY

command.

The format for SETMODE 54 is:

CALL SETMODE (filenumber, 54, , , params);

filenumber

INT:value, is the file number returned by OPEN for the subdevice.

INT:value, the SETMODE number for the 3270 device ID.

params

INT:ref:2, must be provided and returns:

params[0].<0:7> 0 (zero).

params[0].<8:15> subdevice number as known by AM3270.

params[1].<0:7> standard 3270 control unit address.

params[1].<<8:15> standard 3270 device address.

Note that the parameter positions normally used for param1 and param2 are

not used and parameters must not be provided. If they are, a file-system error

2 (invalid operation attempted) will be returned to the caller.