Omron CJ1W-CT021 Operation Manual page 70

Counter Types
CNT1: CNT2:
n+24 n+29
Gating of a Simple Counter
CNT1: CNT2:
n+2 n+5
Presetting a Simple
Counter
50
received count pulses will have no effect. The Over- and Underflow flags can be
cleared by forcing a Preset or a Reset.
15 14 13 12 11 10 9
The Gate of a Simple Counter can be opened and closed using the "Open Gate
Bit" and "Close Gate Bit" in CIO. If the Gate of the Simple Counter is Open the
Counter is ready to count pulses. If the Gate of the Simple Counter is Closed the
Counter will not count pulses. A rising edge of the Open- or Close Gate Bit triggers
the corresponding action in the next I/O Refresh Cycle.
Initially, after the High-speed Counter Unit has been powered up or restarted, the
Gate of the Simple Counter is closed and must be opened first (by setting the
Open Gate bit to '1') to enable counting.
15 14 13 12 11 10 9
A rising edge of the "Open Gate Bit" opens the Gate regardless of the state of the "Close Gate
Bit". A rising edge of the "Close Gate Bit" closes the Gate regardless of the state of the "Open
Gate Bit". At a simultaneous rising edge of both bits, the state of the Gate is unchanged.
The Unit is equipped with a Preset Register that contains the Preset Value for
every (Simple) Counter. To change the Preset Value you can change the Preset
Value in CIO of the corresponding Counter. The Counter Value is overwritten with
the Preset Value at a rising edge of the Preset Counter Bit of the corresponding
8 7 6 5 4 3 2 1
8 7 6 5 4 3 2 1
0
Counter Overflow:
0 = No Overflow
1 = Overflow
Counter Underflow:
0 = No Underflow
1 = Underflow
Simple Counter Indication:
0 = Circular/Linear Counter
1 = Simple Counter
0
Open Gate:
0→1 = Open Gate
Close Gate:
0→1 = Close Gate
Section 3-2