CM3 High-Speed Counter Module Major Functions

Counter Input Mode

Counter Input Mode
Input Method	A-Phase Input	B-Phase Input	Up/Down Counting
1-Phase 2-Multiplication	Direction Input (Low Active)	Pulse Input	A-Phase is low: Up count A-Phase is high: Down count
1-Phase 2-Multiplication	Direction Input (High Active)	Pulse Input	A-Phase is low: Down count A-Phase is high: Up count
2-Phase 2-Multiplication	A-Phase Pulse Input	B-Phase Pulse Input	A precedes B: Up count B precedes A: Down count
2-Phase 4-Multiplication	A-Phase Pulse Input	B-Phase Pulse Input	A precedes B: Up count B precedes A: Down count

1-Phase 2-Multiplication (Low Active)

• The increase or decrease in the direction of the count is dependent on the A-Phase input state.
• The 1-Phase 2 Multiplication input method is not recommended for a system that requires a frequent change in direction because the count value is made by the A-Phase signal.
  • For a precise measurement, 2-Phase 2-Multiplication or 2-Phase 4-Multiplication should be used.

1-Phase 2-Multiplication (High Active)

• The increase or decrease in the direction of the count is dependent on the A-Phase input state.
• The 1-Phase 2 Multiplication input method is not recommended for a system that requires a frequent change in direction because the count value is made by the A-Phase signal.
  • For a precise measurement, 2-Phase 2-Multiplication or 2-Phase 4-Multiplication should be used.

2-Phase 2-Multiplication

• The count is processed when the A-Phase input signal changes.
• The increase or decrease of in the direction of the count is dependent on the state of the B-Phase signal at the moment the A-Phase signal changes.

2-Phase 4-Multiplication

• The count is processed each time the input signals for both A-Phase and B-Phase change.
• The direction of the changing signal and state of the opposing signal determine whether to increment or decrement the count.

Counter Types

The CM3-SP02HSC and CM3-SP02HSD have two counter types.

Linear Counter

• If the count value reaches the maximum value, 2,147,483,647, while incrementing, carry occurs.
• If the count value reaches the minimum value, -2,147,483,648, while decrementing, borrow occurs.
• If carry occurs, counting stops and will no longer increment.
  • Decrementing is still possible.
• If borrow occurs, counting stops and will no longer decrement.
  • Incrementing is still possible.

Ring Counter

• The range for ring counting is from 0 ~ user-defined maximum value.

1. Ring Increment Count:
   • If the count value exceeds the user-defined maximum value while incrementing, carry occurs.
     • The count operation will continue from 0.
   • The carry flag is maintained until the reverse pulse input is entered.

2. Ring Decrement Count:
   • If the count value reaches 0 while decrementing, borrow occurs.
     • The count operation will continue from the user-defined maximum value.
   • The borrow flag is maintained until the reverse pulse input is entered.

If the current count value exceeds the user-defined range when setting up the ring count, it is considered as a user error.

• If an error occurs, it operates the linear count.

Compared Output

• There is 1 compared output function for each channel.
• There are 7 compared output conditions, or modes, available with combinations of >, =, and <.
• In order to use the compared output signal, Enable Compare Output (Y) must be selected in the Channel Configuration window of the special program titled HSC for PLC-S.
• A user can output an external signal by specifying Yn.0 ~ Yn.7 as the compared output signals.
  • n in Yn.0 ~ Yn.7 is the CM3-SP02HSC or CM3-SP02HSD's position on the chassis.

Compared Outputs
Code	Compared Output Conditions
0	Current count < Compared value
1	Current count ≤ Compared value
2	Current count = Compared value
3	Current count ≥ Compared value
4	Current count > Compared value
5	Compared value 1 ≤ Current count ≤ Compared value 2 (inclusive)
6	Current count ≤ Compared value 1 Current count ≥ Compared value 2 (Exclusive)

Counter Latch

• By latching, the counter value is neither cleared nor initialized when the power changes from OFF to ON, and the mode changes.
  • The count continues from the previous value.
    • If a user wants to initialize the current count in this case, the user must use the internal or external preset function.
• The latch counter is activated when Latch Count is selected in the special program HSC for PLC-S.

Input Pulse Count Per Unit Time

• The input pulse count per unit time function counts the number of input pulses for a specified time.
  • To use this function, Unit Time must be set to a value greater than 0.
    • The measured values are updated for each unit time configuration period.
• Unit time (milliseconds):
  • If 0 seconds is selected, this function and RPM/PPS cannot be operated.
• Pulse per 1 Cycle:
  • This is used for the rotations per minute (RPM) function.
    • If the parameter is configured to 0, the RPM function will not operate.
      • The counter works in the pulses per second (PPS) unit regardless of other parameter values.
• The built-in high-speed counter of the PLC-S (mini modular and brick series) counts the input pulse speed through the above parameters.
  • The unit time, pulses per second (PPS), or rotations per minute (RPM) parameters can be selected.

Preset Function

• The preset function changes the current counter value into the configured preset value.
• There is an internal and external preset.
  • The external preset is fixed as an input contact point for each channel.
    • It is activated by a sent signal.
• The external signal for channel 1 (X0004) and channel 2 (X0006) must be used.
• Preset operation begins when the command or input signal is switched from OFF to ON.