Trigger FIELD syntax

FIELDn=record,column,length,(TRIGGER=n,BASE={0 |
TRIGGER}[,DEFAULT=X'value]')

Options and values

n
The field parameter identifier. When adding a field parameter, use the next available number, beginning with 1 (one). The value must be between 1 and 128.
record
The relative record number from the trigger on which the field is based. This is the record number where the 400 indexer begins to search for the field. The supported values include any number from -255 to 255, including 0.
column
The relative column number from the BASE. This is the column number where the 400 indexer searches for the field. A value of 1 (one) refers to the first byte in the record. For files containing carriage-control characters, column one refers to the carriage-control. If you specify BASE=0, the column value can be 1 to 378. If you specify BASE=TRIGGER, the column value can be -378 to 378.
length
The number of contiguous bytes (characters) that compose the field. The supported range of values is 1 to 250. The field can extend outside the record length, if the column where it begins lies within the record length. In this case, the 400 indexer adds padding blanks to fill out the field. Depending on the code page of your data, some characters might require more than one byte of data for each printed character. For example, DBCS data requires at least two bytes for every character. Data stored in an instance enabled with UTF-8 (Unicode) support requires one, two, or three bytes for each character, depending on the code page of the original data. See the IBM® Content Manager OnDemand for i: Common Server Planning and Installation Guide for more information on UTF-8 support.
TRIGGER=n
Identifies the trigger parameter the 400 indexer uses to locate the field. This is an optional parameter, but the default is TRIGGER1. Replace n with the number of a defined TRIGGER parameter.
BASE={0|TRIGGER}
Determines whether the 400 indexer uses the starting column number of the trigger string value to locate the field data. Choose from 0 (zero) or TRIGGER. If BASE=0, the 400 indexer adds zero to the field column offset. If BASE=TRIGGER, the 400 indexer adds the starting column number of the trigger string value to the field column offset. You should use BASE=0 if the field data always starts in a specific column. You should use BASE=TRIGGER if the field data doesn't always start in a specific column, but is always offset from the trigger string value a specific number of columns. For example, a trigger occurs in the second record on a page. The trigger string value can begin in any column in the record. A field based on this trigger occurs in the trigger record. In the example, the starting column number of the field is always 10 bytes from the starting column number of the trigger. Specify BASE=TRIGGER and a column offset of 10 so that the 400 indexer correctly locates the field, regardless of the starting column of the trigger string value.
DEFAULT=X'value'
Determines the default value for the index when the field is not found in the page group. The default value must be specified as an EBCDIC hexadecimal string. For example, X'value'.
Example
The following field parameter causes the 400 indexer to locate field values that begin in column 83 of the same record that contains the TRIGGER1 string value. The field length is 8 bytes. Specify BASE=0 because the field data always starts in the same column.
TRIGGER1=*,1,X’F1’,(TYPE=GROUP)
FIELD1=0,83,8,(TRIGGER=1,BASE=0)
The following field parameter causes the 400 indexer to locate field values that begin 10 columns offset from the trigger string value. The trigger string value can start in any column in any record. Basing the field on TRIGGER2 and specifying BASE=TRIGGER allows the 400 indexer to locate the field by adding 10 to the starting column offset of the trigger string value.
TRIGGER2=*,*,X’E2A482A396A38193’,(TYPE=FLOAT) 
FIELD2=0,10,12,(TRIGGER=2,BASE=TRIGGER)