The following data types are supported by the MIF:

integer (or int)

A 32-bit signed integer with no known semantics
integer64 (or int64)
A 64-bit signed integer with no known semantics
gauge
A 32-bit unsigned integer that can increase or decrease. When a gauge reaches its maximum value (2[32]-1), it continues to report the maximum value until the value decreases below the maximum. The speedometer of an automobile is an example of a gauge.
counter
A 32-bit unsigned integer that never decreases. A counter increases to its maximum value (2[32]-1 or 2[64]-1) and reverts to zero when it reaches its maximum value. The odometer of an automobile is an example of a counter.
counter64
A 64-bit unsigned integer that never decreases. A counter increases to its maximum value (2[32]-1 or 2[64]-1) and reverts to zero when it reaches its maximum value.
string(n) or displaystring(n)
A displayable string of n octets. For ISO 8859-1 implementations, 1 octet per character; for Unicode implementations, 2 octets per character.

The value n represents the maximum number of octets in the string, although the actual number of octets in use might be shorter than this maximum value. The length of the string is stored in the first four octets, which are not included in the value n. You do not need to zero-terminate the string as you do in the C and C++ programming languages. The length of the string represents the number of octets in the string, not the number of characters.

The maximum value of n that the service layer can display is 508.

octetstring(n)
A string of n octets that might or might not be displayable.

The value n represents the maximum number of octets in the string, although the actual number of octets in use might be shorter than this maximum value. The length of the string is stored in the first four octets, which are not included in the value n. You do not need to zero-terminate the string as you do in the C and C++ programming languages. The length of the string represents the number of octets in the string, not the number of characters.

date
A 28-octet displayable string.

Dates are defined according to the following format:

yyyymmddHHMMSS.uuuuuu+ooo

Where:

yyyy

The year
mm
The number of the month
dd
The number of the day of the month
HHMMSS
The hours, minutes, and seconds, respectively
uuuuuu
The number of microseconds
ooo
The offset from universal time, coordinated (UTC) in minutes. If east of UTC, the number is preceded by a plus (+) sign, if west of UTC, the number is preceded by a minus (-) sign,
While the date value occupies only 25 octets, the date is stored as a 28-octet field to account for memory alignment. The last three octets are zeroes (/0).

For example, Wednesday, May 25, 1994, at 1:30:15 PM EDT would be represented as:

19940525133015.000000-300

If necessary, values must be padded with leading zeroes to conform to the specified format, as in 05 being used to represent the month of May. If a value is not supplied for a field, each character in the field must be replaced with an asterisk (*).

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