Device-dependent input information (3270 or SLU 2)

Cursor location

As an option of the MFS Language utility, a field in the message can contain the location of the cursor on the device when input was transmitted to IMS. This option is only available for 3270 or SLU 2 display devices and its use can make programs device-dependent. The format of the cursor information is two 2-byte binary numbers, the first containing the line number, the second containing the column number. The minimum value for the line or column is 1. For 3270-An device types, the maximum value for the line is the first parameter of the SIZE= operand; the maximum value for the column is the second parameter of the SIZE= operand.

The table below lists the maximum line and column values for MFS device types.

Selector pen

Use of the selector light pen can affect input fields in several ways:

• If the ATTR output field option is not used dynamically to create detectable fields, the following occurs:
  • A message field that refers to device fields defined with the attributes DET,STRIP is presented as a device-independent field.
  • The first data byte available for the message field is the byte beyond the designator character in the device field.
  • A message field that references device fields defined with the attributes IDET,STRIP is also presented with device-independent data.
  • The designator character is removed.
  • Data from this field is not presented if no modified fields exist on the device when the field is selected. In this case, the only device information available for the message is the value specified for literal on the PEN= operand of the DFLD statement.
• If the ATTR output field option is used dynamically to create detectable fields, then the following occurs:
  • Fields dynamically established as either deferred detectable or immediate detectable do not have designator characters removed from input.
  • If a field altered to immediate detectable is selected when no other fields on the device are modified, no device input data is available for the message.
• If a message field is defined to receive immediate detect selector pen literal data, one of the following occurs:
  • If device input is not the result of an immediate selector pen detect, the field is padded as requested.
  • If device input is the result of an immediate selector pen detect, but at least one other field on the device is modified, one data character of a question mark (?) is presented in the field with the requested padding.
  • If the device input is the result of an immediate selector pen detect and no other modified fields exist on the device, that literal is placed in the message as requested if the detected field is defined with a PEN=literal. If the detected field is not defined with a PEN=literal, one data byte of a question mark (?) is placed in the message field. In either case, no other device information is provided.
• If an EGCS attribute is defined for a light-pen-detectable field, you should specify ATTR=NOSTRIP on the DFLD statement and design your application program to bypass or remove the two designator characters from the input data. If ATTR=STRIP is specified or defaulted, MFS removes only the first designator character and truncates the last data character in the field.

Magnetic stripe reading devices

The use of magnetic stripe reading devices is transparent to the application program. For operator identification (OID) card readers, the framing characters (SOR, EOR, EOI, LRC) are removed and parity checking is performed before editing.

Program function keys

Use of program function keys is transparent to the application programs.

Program access keys

Program access key information is not available to application programs.