Hitachi NJI-350B manual High ↓ Falling edge, ↓ Falling edge Low ↑ Rising edge High

Chapter 8 High-speed counter, PWM / Pulse train output and Analogue I/O

(2)Phase counting mode 1

In this mode the counter counts at the rising edge of input 1A. At this point, if input 1B is 0 (Low) it counts up, and if input 1B is 1 (High) it counts down.

Input 1A

Input 1B

Count value

Off preset

On preset

Coincidence output

Figure 8.15 Counting operation of phase counting mode 1

Input 1A	Input 1B	Operation
1 (High)	↑ (Rising edge)	Do not count
0 (Low)	↓ (Falling edge)
↓ (Falling edge)	1 (High)
↑ (Rising edge)	0 (Low)	Up count
0 (Low)	↑ (Rising edge)	Do not count
1 (High)	↓ (Falling edge)
↓ (Falling edge)	0 (Low)
↑ (Rising edge)	1 (High)	Down count

(3)Phase counting mode 2

In this mode, if input 1B is 0 (Low) at the rising edge of input 1A the counter counts up, and if input 1A is 0 (Low) at the rising edge of input 1B, the counter counts down.

Input 1A

Input 1B

Count value

Off preset

On preset

Coincidence output

Figure 8.16 Counting operation of phase counting mode 2

Input 1A	Input 1B	Operation
1 (High)	↑ (Rising edge)	Do not count
0 (Low)	↓ (Falling edge)
↓ (Falling edge)	1 (High)
↑ (Rising edge)	0 (Low)	Up count
0 (Low)	↑ (Rising edge)	Down count
1 (High)	↓ (Falling edge)	Do not count
↓ (Falling edge)	0 (Low)
↑ (Rising edge)	1 (High)

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