IDEC FT1A Series User Manual page 107

Comparison operation flow
The comparison operation flow is as follows.
1. Start (run) the SmartAXIS.
For the first scan, Next Preset Value 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 Preset Value Number is transferred
to Current Preset Value Number.
The content of Next Preset Value Number becomes the preset value n + 1 ("2" in this example).
When the number of preset values is 1, Next Preset Value Number is always "1".
Start the high-speed counter count operation.
2.
Turn on the gate input to start the count operation.
3. Compare the Current Preset Value Number preset value and the current value. When the current value and the preset
value 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 Preset Value Number with Next Preset Value Number and start the count with the preset value for Current Preset
•
Value Number.
Add 1 to Next Preset Value Number.
•
When the procedure is executed up to preset value 6, repeat again from the beginning with preset value 1.
4.
Note: The Current Preset Value Number data register cannot be written to. It is read-only. Next Preset Value Number and Preset Value 1
to Preset Value 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)
S AXIS P /L U '
MART RO ITE SER S
Group 1
Read/Write
(I0 to I1)
D8052
R/W
D8053
M FT9Y-B1378
ANUAL
5: S F
PECIAL UNCTIONS
5-19