CONFIGURATION
FUNCTION BLOCKS
I-E96-207A
4 - 3
FUNCTION BLOCKS
The IMCOM03/04 has 240 function blocks available for user
configuration. Of these, blocks 0 through 9 are fixed (their val-
ues are preassigned; you can not alter them), and block 240 is
reserved.
NOTE: The total number of blocks actually configurable for user
selected functions depends on several critical factors: Execution
time, memory utilization, degree of complexity, etc. Refer to the
Function Code Application Manual, I-E93-900-20 for utilization
factors for each function code.
The following example uses three function blocks. The steps
below determine how to calculate the memory and CPU
utilization.
1. Identify memory utilization and execution time:
2. Specify the number of blocks. In this example, 15 Square
Root blocks, 15 PID blocks and 1 Executive Block are config-
ured.
3. Calculate the amount of memory the configuration uses:
a. Multiply 15 PID blocks by 2.5% per block = 37.5%
used.
b. Multiply 15 Square Root blocks by 0.7% per block =
10.5% of used.
c.
Note that the Executive Block uses 0.0% used.
d. Add products: 37.5%
10.5%
47.0%
There is 53.0% of memory remaining.
4. Calculate the amount of CPU time the configuration
requires to run.
a. Multiply 15 PID blocks by 20.100 milliseconds.
Function Code 7
Square Root
0.7% memory
12,500 microseconds execution rate.
Function Code 19
PID
2.5% memory
20,100 microseconds execution rate.
Function Code 53
Executive Block
0.0% memory
600 microseconds execution rate.
