FieldPlane

The field plane represents the field positions and their attributes in the presentation space. This plane is meaningful only for field-formatted presentation spaces. (For example, VT connections are not formatted).

This plane is a sparse-array of field attribute values. All values in this plane are binary zero except for where field attribute characters are present in the presentation space. At those positions, the values are the attributes of the field which starts at that location. The length of a field is the linear distance between the field attribute position and the next field attribute in the presentation space, not including the attribute position itself.

The value of the field attribute positions are as shown in the following tables.

Note: Attribute values are different for different types of connections.

Table 1. 3270 Field Attributes
Bit Position (0 is least significant bit)	Meaning
7	Always "1"
6	Always "1"
5	0 Unprotected 1 Protected
4	0 Alphanumeric data 1 Numeric data only
3, 2	0, 0 Normal intensity, not pen detectable 0, 1 Normal intensity, pen detectable 1, 0 High intensity, pen detectable 1, 1 Nondisplay, not pen detectable
1	Reserved
0	0 Field has not been modified 1 Unprotected field has been modified

Table 2. 5250 Field Attributes
Bit Position (0 is least significant bit)	Meaning
7	Always "1"
6	0 Nondisplay 1 Display
5	0 Unprotected 1 Protected
4	0 Normal intensity 1 High intensity
3, 2, 1	0, 0, 0 Alphanumeric data 0, 0, 1 Alpha only 0, 1, 0 Numeric shift 0, 1, 1 Numeric data plus numeric specials 1, 0, 1 Numeric only 1, 1, 0 Magnetic stripe reading device data only 1, 1, 1 Signed numeric only
0	0 Field has not been modified 1 Unprotected field has been modified

Table 3 defines the various mask values:

Table 3. Mask Values
Mnemonic	Mask	Description
FATTR_MDT	0x01	Modified field
FATTR_PEN_MASK	0x0C	Pen detectable field
FATTR_BRIGHT	0x08	Intensified field
FATTR_DISPLAY	0x0C	Visible field
FATTR_ALPHA	0x10	Alphanumeric field
FATTR_NUMERIC	0x10	Numeric only field
FATTR_PROTECTED	0x20	Protected field
FATTR_PRESENT	0x80	Field attribute present
FATTR_52_BRIGHT	0x10	5250 intensified field
FATTR_52_DISP	0x40	5250 visible field