Section 9. Input/Output Instructions
9-3
High Frequency Input
•
Pulse Channels
Minimum Pulse Width: 1.2 microsecond
Maximum Frequency: 16 kHz
(8 Bit Counter, 50% Duty Cycle,
64 Hz Reset)
Maximum Frequency: 400 kHz
(16 Bit Counter, 50% Duty Cycle)
Lower Threshold: 1.5 V*
Upper Threshold: 3.5 V*
When a pulse channel is configured for high-frequency pulse, there is an
internal 100 kohm pull-up resistor to 5 V on the pulse channel. This pull-up
resistor accommodates open-collector output devices for high-frequency
input.
*Larger input transitions are required at high frequencies because of the input RC
filter with 1.2 microsecond time constant. Signals up to 400 kHz will be counted
if centered 2.5 V with deviations
≥
±
2.5 V for
≥
1.2 microseconds.
Low Level AC (Pulse Channels Only)
Input Hysteresis: 15mV
Maximum Input Voltage: 20V peak-to-peak
Input Voltage and Frequency Range
(64 Hz reset required above 2 kHz)
20 mV
1.0 Hz to 1 kHz
200 mV
0.5 Hz to 10 kHz
1000 mV 0.3 Hz to 16 kHz
Switch Closure
•
Pulse Channels
A switch closure is connected between P1..P4 and analog ground. When
the switch is open, the CR10X pulls the pulse channel to 5V through a
100 kOhm impedance. When the switch is closed, the pulse channel is
pulled to ground. The count is incremented when the switch opens.
Minimum Switch Closed Time: 5 ms
Minimum Switch Open Time: 6 ms
Maximum Bounce Time: 1 ms open without being counted
•
Control Ports
The switch closure is connected between channels C6..C8 and the 5V
terminal. When the switch is open, the control port is pulled to ground
through an internal 100kOhm resistor. When the switch is closed, the
control port is at 5V. The count is incremented when the switch closes.
Maximum Frequency: 40 Hz
Minimum Switch Closed Time: 6 ms
Minimum Switch Open Time: 6 ms