Mapping Services Facility › Type Description and Formats › BIT STRING Type › Standard BIT STRING Access › Local Form and Behavior

Local Form and Behavior

When a string of 0’s and 1’s is supplied as input, each digit in the input sequence is treated (left to right) as the value of the corresponding bit in that position of the local form data. If the number of bits supplied is not a multiple of 8, trailing bits are set to zero and padded to a byte boundary. If the component has a fixed length exceeding that of the input string, the value is left aligned, and all unreferenced bytes are set to X’00’. If the component cannot contain the number of input bytes supplied, the string is truncated.

When a list of named values, each preceded by a plus sign (+) or a minus sign (-), is supplied as input, only the named bits take part in the operation. Each named bit preceded by a plus sign (+) is set to 1 (true), and each named bit preceded by a minus sign (-), is set to 0 (false). All other bits in the BIT STRING are unaffected by the input operation.

When fetching the value of a BIT STRING a named value list is always returned if any named values are defined for the type, else a string of 0s and 1s is returned corresponding to the BIT STRING values. Note that when named values are defined all other bits in the BIT STRING are ignored on output regardless of their value.