Echelon LonTal Stack - Manual (Page 207)

LonTalk Stack Developer’s Guide 195
Memory Use for Buffers
The Buffer Configuration page of the LonTalk Interface Developer utility allows
you to specify the number of input, output, and priority output application
buffers that your LonTalk Stack application should use. The values that you
specify in the utility are defined in the FtxlDev.h file that the utility generates.
The LonTalk host stack uses the number of application buffers that you specify to
allocate memory for both the application buffers and related internal buffers.
Some of the internal buffers are allocated in advance, and some are allocated on
an as-needed basis.
The following table lists the estimated amount of memory required for each type
of application buffer.
Application Buffer Type Bytes Required
Input buffer 1710
Output nonpriority buffer 1118
Output priority buffer 1118
The default numbers for each type of buffer are: 5 input buffers, 5 output
nonpriority buffers, and 1 output priority buffer. The RAM usage for the default
number of application buffers is approximately 15 KB.
Memory for L
ON
W
ORKS
Resources
Each LonTalk Stack device uses L ON W ORKS resources, such as network variables
defined for the device, address table entries, and aliases supported by the device.
The LonTalk host stack allocates memory only for resources that are in use. For
example, it allocates memory for address table entries only if the address is
bound. To calculate maximum memory requirements, assume that all resources
are in use.
The following table lists the estimated amount of memory required for each type
of L
ON W ORKS resource. For example, network variables can vary in their actual
sizes, so the table uses an average value.
Resource Type Bytes Required
Static network variable 320 + SD_length + NV_length
Dynamic network variable 331 + SD_length + NV_length
Alias 220
Address table entry 67