Analog (Ain); Analog Input Offset; A/D Refresh Rate - Danfoss PLUS+1 Series Technical Information

Technical Information
Inputs/Outputs Types and Specifications
PLUS+1® Controller Family
Specifications (continued)
Description
Falling voltage threshold
Time to change state in response to
step input
Input impedance
Input voltage < 5.7 Vdc
Input impedance
Input voltage < 5.7 Vdc
Input impedance
Input voltage ≥ 5.7 Vdc

Analog (AIN)

Specifications
Description
Allowed voltage at pin *
0 to 5 Vdc range Maximum
discernable voltage
0 to 36 Vdc rangeMaximum
discernable voltage
Precision
Input impedance

Analog Input Offset

Module analog input offset error can be 80 counts out of 4096 (12 bit resolution). Therefore, the
minimum voltage that a module will read at the 0 to 5.25 Vdc range is 105 mV. The minimum voltage that
a module will read at the 0 to 36 Vdc range is 703 mV.
The input offset error is a function of component tolerances and can vary from one module to the next.
When an input value is used in an algorithm where the offset error could impact the control strategy, the
way the signal is acquired and the need to calibrate should be considered.

A/D Refresh Rate

Analog to Digital (A/D) refresh rates for individual PLUS+1 modules are as follows. A/D channels are
sampled at 25 kHz and 64 samples are taken to build an average value. This results in a refresh rate of 2.56
ms for channels directly measured. All internal current feedback channels are refreshed at the 2.56 ms
rate.
Some PLUS+1 module A/D channels are shared. Each of the shared channels has eight multiplexed
analog inputs. Each multiplexed input is serviced every 20.48 ms. Update rates for specific analog input
520L0719 • Rev PB • Feb 2014
Units Minimum Maximum
Vdc 1.01 2.77
ms 1.5
kΩ
kΩ
kΩ
Units Minimum Maximum
Vdc 0 36**
Vdc 5.21 5.30
Vdc 31.70
mV 1.28
kΩ 206 236
Comment
A digital input is guaranteed to be read
as low if the voltage is less than 1.01
Vdc.
Input change from maximum to
minimum—add to debounce time.
233 nominal—no pull up or pull down
pin configuration.
14.1 nominal—pull up or pull down pin
configuration.
14.1 nominal—all pin configurations.
Comment
* Maximum allowed voltage on fixed
range analog input pins (CAN shield)
is 25 Vdc.
** MC050-055/05B input voltage
maximum is limited to 16 Vdc.
5.26 is typical.
Depends on pin configuration.
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