11.6 Pulse measurement specifications
The data logger can measure switch closure or high-frequency pulse signals on C and U
terminals. Terminals are configured as pairs with options for pull-up or pull-down. Even-
numbered U terminals can be configured as low-level AC inputs. See also
(p. 222). Each terminal has its own independent 32-bit counter. Terminal pairs are
U1 and U2, U3 and U4, through U11 and U12.
NOTE:
Conflicts can occur when a control port pair is used for different instructions (
TimerInput
()
,
PulseCount()
,
SDI12Recorder()
,
WaitDigTrig()
). For example, if C1 is used
for
SDI12Recorder()
, C2 cannot be used for
TimerInput()
,
PulseCount()
, or
WaitDigTrig()
.
Pulse Event: Transition from logic low to logic high.
Terminal Pair Configuration Logic Low Logic High
5 V
≤ 1.5 V
≥ 3.5 V
3.3 V
≤ 0.8 V
≥ 2.0 V
Maximum Input Voltage: ±20 VDC
Maximum Counts Per Channel: 2
32
Maximum Counts Per Scan: 2
32
Input Resistance: 5 kΩ
Accuracy: ±(0.02% of r 1/scan)
11.6.1 Switch closure input
Terminals: C1-C4, U1-U12
Resistance: Configurable in terminal pairs with 100 kΩ pull-up or pull-down
Maximum Input Frequency: 150 Hz
Minimum Switch Closed Time: 5 ms
Minimum Switch Open Time: 6 ms
Maximum Bounce Time: 1 ms open without being counted
Software Debounce Time: 3.3 ms
11. CR6 Specifications
221