Counter Circuit - IDEC MICROSmart FC6A Series Ladder Programming Manual

Counter Circuit

The preset value 0 through 65,535 can be designated using a data register D0 thorough D7999 or D10000 through D61999; then
the data of the data register becomes the preset value.
Directly after the CNT instruction, the OUT, OUTN, SET, RST, TML, TIM, TMH, or TMS instruction can be programmed.
Ladder Diagram
Reset
CNT C28
D5
I0
Pulse
I1
Note: For restrictions on ladder programming of counter instructions, see "Restriction on Ladder Programming" on page 4-33.
Valid Pulse Inputs
The reset or preset input has priority over the pulse input. One scan after the reset or preset input has changed from on to off, and
the counter starts counting the pulse inputs as they change from off to on.
ON
Reset/Preset
OFF
ON
Pulse
OFF
More than one scan
time is required.
• The reset input must be turned off before counting may begin.
• When power is off, the preset values that were changed are cleared and the original preset values are loaded.
• When power is off, the counter's current value is held, and can also be designated as "clear" type counters using Function Area Settings (see
Chapter 5 "Memory Backup" in the "FC6A Series MICROSmart User's Manual".).
• Counter preset and current values can be changed using WindLDR without downloading the entire program to the CPU again. From the
WindLDR menu bar, select Online > Monitor > Monitor, then Online > Custom > New Custom Monitor. Change the current value
while the counter reset input is off.
• When the preset or current value is changed during counter operation, the change becomes effective immediately.
• WindLDR ladder diagrams show CP (counter preset value) and CC (counter current value) in advanced instruction devices.
• For data movement when changing, confirming, and clearing preset values, see "Changing, Confirming, and Clearing Preset Values for Timers
and Counters" on page 4-19. Preset values can also be changed and confirmed using the LCD screen and pushbuttons.
• If used, a user program execution error will result, turning on special internal relay M8004 and the ERR LED on the FC6A Series MICROSmart.
For details about the user program execution errors, see "User Program Execution Errors" on page 3-10.
Counter Operation after Count out
When the counter has counted out, either the current value or preset
value is changed.
Before the counter has counted out, the current value is changed to a
larger value than the preset.
The preset value is changed to 0.
When the reset input is on, the preset value is changed to 0.
Program List
Instruction
Q0
Valid Invalid Valid
Condition
FC6A S MICROS
ERIES MART
Data
LOD I0
LOD I1
CNT C28
OUT Q0
The counter maintains the counted out status.
The counter output is turned on.
The counter output is turned on without regard to the current value.
The counter output is not turned on.
L P M
ADDER ROGRAMMING ANUAL
4: B
ASIC
Counter Output
FC9Y-B1726
I
NSTRUCTIONS
4-15