Description of functions
Copyright IXXAT Automation GmbH
13
CANio 500 Quickstart Manual, version 1.3
If a single-ended signal is required, the corresponding input ANA_INx_M is to
be connected to ground.
The voltage is measured between the two connections (P +plus and M -
minus). The common mode range is from -12 V to +24 V, i.e. both inputs may
not exceed this voltage. Voltages above this lead to incorrect results.
The inputs are protected up to 60 V. The inputs have a low-pass filter to mini-
mize disturbances. The filter used is a simple grade 1 filter with an RC circuit
set to a cut-off frequency
3 dB
of approximately 1 kHz.
The input resistance of the device versions with a voltage input is approx. 80
k
Ω. In the case of the device versions with a current input, a shunt resistor of
15 Ohm is used for current measurement.
The CANio 500 is a high quality instrument to measure voltages and currents.
The voltage values (or current values) must be calculated with the formulae
given in the following chapters. To increase the accuracy in the application, it
may be necessary to calibrate the CANio 500. For this, the user must measure
and record 2 to 3 different voltage values for each channel and calculate a cor-
rection curve or table from these.
4.6.1 0 - 10 V input range
The voltage on the input with an input range of 0 - 10 V can be calculated from
the AD value as follows:
U
ANA-IN
= AD value / 4095 * 3.30 * 3.3271 [V]
Simplified:
U
ANA-IN
= AD value * 2.6812 [mV]
4.6.2 ±5V input range
The voltage on the input with an input range of ±5 V can be calculated from
the AD value as follows:
U
ANA-IN
= (AD value / 4095 * 3.30 * 3.3271)
– 5.00 [V]
Simplified:
U
ANA-IN
= AD value * 2.6812
– 5000 [mV]