# Defining parameters

Natural Access parameters are a mechanism to allow the operating characteristics of a service to be dynamically modified. If the service being developed needs this type of extensibility, then define a set of one or more parameters. Parameters are named entities with the following syntax:

xxx.category.fieldname

A parameter category is like a directory in a modern file system. It allows multiple logically-related fieldnames to be nested. For example, the ADI service contains multiple categories, each of which contain multiple fieldnames:

ADI.CALLPROG.busycount
ADI.CALLPROG.leakagetime
ADI.CALLPROG.maxbusy
ADI.COLLECT.firsttimeout
ADI.COLLECT.intertimeout

A data type and a default value are associated with each parameter. Supported data types are:

Data type | Description
--- | ---
WORD | 16 bit unsigned integer
DWORD | 32 bit unsigned integer
INT16 | 16 bit signed integer
INT32 | 32 bit signed integer
STRING | Arbitrary length string which may contain spaces
BYTE_ARRAY | Array of bytes

tik service

For the tik service, there is one category comprised of two field names:

Number of tick strings to be received = tik.start.NumTicks

data type = DWORD, default = 2

Frequency of tick strings to be received = tik.start.Frequency

data type = DWORD, default = 2