Programming
Chapter 3
34
to complete, all other true AF1 function rungs will be “locked out” until
sufficient program scans complete the active AF1 function rung.
Once started, it completes an AF1 function prior to starting the next AF1
function encountered in the user program which has a true rung condition.
Limits the number of enabled AF1 functions in a program to 50. You may
include more functions but you must ensure that no more than 50 are enabled
at one time. This requirement only applies where you have programmed a
function that requires more than one scan to complete.
Table 3.B
Execution
T
ime
[1]
Function Avg. Time Worst Time Number or Scans
Addition 1.22ms 1.27ms 1
Subtraction 1.22ms 1.27ms 1
Multiplication 4.99ms 5.28ms 1
Division 16.17ms 21.76ms 4
Square Root 6.08ms 7.11ms 1
Average 12.33ms
+0.29ms per value
4 + N / 4
[2]
Standard Deviation 94.16ms
+2.09ms per value
22 + 5N / 4
[2]
BCD to Binary 0.89ms 1
Binary to BCD 0.84ms 1
[1]
These times are calculated for a single AF1 function. Overhead for AF1 lock maintenance and
multiple rungs through the ladder program to complete some function are included
[2
]
N=number of values whose average or standard deviation is sought.
The time listed in Table 3.B includes:
Overhead for AF1 PROM interlock system
One run through the portion of the AF1 specified by the particular function
