UMAX180800, 20 Thermocouple, 2 RTD, 4 Inputs, 6 Relays Dual CAN Controller
Version 1
Page: 18-71
Parameter
Default Value
Range
Units
Description
Frequency/PWM
Debounce Filter
3
0 - Disabled
0 - Disabled,
1 - 142ns,
2 - 1.14us,
3 - 6.10us
–
Used in "Frequency", and
"PWM Duty Cycle"
modes.
Frequency/PWM
Averaging
0 - No
Averaging
0 - No Averaging,
1 - 3 Readings,
2 - 5 Readings,
3 - 10 Readings
–
Defines a moving
average filer used in
"Frequency", and "PWM
Duty Cycle" modes.
1
Input currents below 3mA are output as 0mA when
4…20 mA current range is set.
3.3.1 Voltage Measurements
The
Universal Inputs
can measure voltages in voltage ranges set by the
Voltage Range
configuration parameter.
To avoid an influence of ghost voltages, the
Voltage LoZ Input
configuration parameter can be
activated. This will reduce the accuracy of voltage measurements due to the influence of the
10kOhm pull-down shunt resistor and should be used only after careful consideration of the
shunt resistor influence on the measured circuit.
The user can set the
Analog Input Filter
configuration parameter to reduce noise in voltage and
other analog signal measurements. The filter is designed to suppress noise from industrial
offline voltages. Even when the analog input filter is disabled, the minimum signal filtering is
performed by the function block. The parameters of the analog input filter
are presented below.
Table 8. Universal Input Analog Input Filter Parameters
Analog Input Filter
Cut-off Frequency
(at -3dB)
Settling Time
(to 100% of Final Value)
Output Signal Update Rate
Disabled
1
70Hz
10ms
1.67ms
50Hz Noise Rejection
12Hz
76.7ms
3.33ms
60Hz Noise Rejection
14Hz
63.3ms
3.33ms
Both: 60Hz and 50Hz
Noise Rejection
2.3Hz
396.7ms
16.67ms
1
Minimum filtering is still performed.
3.3.2 Current Measurements
There are two standard current ranges available for current measurements. When the current
is below 3mA in the
“4…20mA” current range, the output will be forced to zero to facilitate
detection of an open circuit condition on the
Universal Input
.
The
Analog Input Filter
can be set to reduce the input noise.
3.3.3 Discrete Voltage Level
The
Universal Inputs
can accept discrete voltage levels. The user should specify the input
polarity and define whether the pull-up/pull-down resistor is necessary on the input.
When the “10kOhm Pull-Up” is selected, the pull-up resistor is connected to the in14V
power supply.
