IDEC MICROSmart FC6A Series User Manual page 269

Comparison operation flow
The comparison operation flow is as follows.
1. Start (run) the FC6A Series MICROSmart.
For the first scan, Current Comparison Number is set to 0, and Next Comparison Number is set to the number for preset
value 1 with the initialize pulse.
For the second scan, an I/O refresh is performed in END processing and the value of Next Comparison Number is transferred
to Current Comparison Number.
The content of Next Comparison Number becomes the preset value n + 1 ("2" in this example).
When Number of Comparisons is 1, Next Comparison Number is always "1".
Start the high-speed counter count operation.
2.
Turn on the gate input to start the count operation.
Compare the Current Comparison Number preset value and the current value. When the current value and the preset value
3.
match, the next number for the preset value becomes active and the high-speed counter continues counting.
Execute Comparison Output or Interrupt Program. (Comparison Output in this example)
Turn on the comparison (special internal relay) for only one scan.

Overwrite Current Comparison Number with Next Comparison Number and start the count with the preset value for Current

Comparison Number.
Add 1 to Next Comparison Number.

When the procedure is executed up to preset value 6, repeat again from the beginning with preset value 1.
4.
Note: The Current Comparison Number data register cannot be written to during the count action. It is read-only. Next Comparison Number
and Comparison 1 to Comparison 6 can be read and written to.
The data register that stores the preset value (target value).
Specify the starting address.
The outputs (external outputs) when the values match.
Transfer
The preset value with the number that became active is the
comparison subject with the current value and is stored in the special
data registers.
Example: For group 1
Storage destination for the preset value that became active.
Stored by group.
Group
Preset Value
(Upper word)
Preset Value
(Lower word)
FC6A S MICROS U
ERIES MART
1 Read/Write
D8212
R/W
D8213
' M FC9Y-B1722
SER S ANUAL
5: F S
UNCTIONS AND ETTINGS
5-23