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INTRODUCTION
I-E96-213A
4 - 1
SECTION 4 - CONFIGURATION
INTRODUCTION
A variety of control and math functions reside in the module's
firmware. These are known as function codes. These codes,
when assigned to addresses in NVM, become function blocks.
Users link these function blocks sequentially to perform their
control strategy.
This section explains the configuration process. (For complete
information about MFC function codes, refer to E93-900-20,
Function Code Application Manual).
FUNCTION BLOCKS
The IMMFC05 has 2,047 function blocks available for user
configuration. Of these, blocks 0 through 29 are fixed (their
values are preassigned; the user cannot alter them), and block
2,047 is reserved.
NOTE: The total number of blocks actually configurable for user
selected functions depends on several critical factors: Execution
time, bytes of NVM and RAM, degree of complexity, etc. Refer to the
Function Code Application Manual, E93-900-20 for utilization factors
for each function code.
The following example uses three function blocks and three dif-
ferent execution times. The steps below determine how to cal-
culate the memory and CPU utilization based on a low priority
loop time of two seconds.
1. Identify NVM and RAM utilizations and execution times:
Function Code 7 Square Root
12 Bytes NVM
44 Bytes RAM
240 microseconds execution rate
Function Code 19 PID
36 Bytes NVM
116 Bytes RAM
690 microseconds execution rate
Function Code 82 Segment Control
60 Bytes NVM
256 Bytes RAM
In this example, execution time for this function is negligible.