Start Field (Sf) Order - Intermec CK30 Programmer's Manual

—
Chapter 6 Data Stream Commands

Start Field (SF) Order

248
The SF order notifies the terminal that the next byte in the write data
stream is an attribute character. The terminal stores the next byte and
attribute character at the current buffer address. As the attribute character
is stored, the terminal sets a control bit at the address. This bit identifies
the byte as an attribute character during subsequent program or device
operations with the buffer data.
Note: The byte immediately following the SF order in the data stream is
always stored as an attribute character, even when the byte is intended as
an order or an alphanumeric data character.
The byte following the SF order defines the characteristics or "attributes"
of the data that follows. Each attribute character, plus all the data follow-
ing it up to the next attribute character (or the last location of the buffer)
is called a field.
In addition to defining the start of a field, attribute characters define these
characteristics for all character locations contained within the field:
S Protected from modification by the user, or unprotected (available for
the operator to modify or enter data). The unprotected definition classi-
fies the field as an input field.
S Alphanumeric (an input field in which the operator can enter alpha-
betic, numeric, or symbol characters) or numeric (an input field in
which the period, dash, and numbers 0-9 may be used).
S Field displayed or not displayed to the user.
TE 2000
™
3270 Terminal Emulation Programmer's Guide