Programming
Chapter 3
32
Table 3.A
AF1
Function Numbers
Function
Number
Mathematical Operation
01 Add
02 Subtract
03 Multiply
04 Divide
05 Square root
06 Average
07 Standard deviation
13 BCD to binary conversion
14 Binary to BCD conversion
You enter an existent function number and then enter data and result addresses
(we will explain this in detail later). The processor then places a number in the
data address.
When the Mini-PLC-2/15 controller encounters an AF2 function during
program execution and the rung is true, the processor performs the following
steps:
1. Saves its present position in the user program.
2. The interlock system (see Avoiding Excessive AF1 Execution Times)
grants access to the AF1 function.
3. Reads the operand’s data stored in the data address that you entered.
4. Reads the result address which you entered.
5. Obtains the location of the mathematical routine requested by the function
number.
6. Executes the routine in the AF1 area. (See section for excessive execution
time.)
7. Writes the results at the result address in the data table.
8. Returns program execution to the next instruction in the user’s program
after the AF1 function is completed. (See section for excessive execution
time.)
9. Readies itself for the next AF1 operation.
AF1 Function Sequence
