Functions of the board
APCI-3701
40
The board
APCI-3701
has up to 16 analog inputs. It is typically designed for
acquiring measurement signals of inductive displacement transducers. Therefore
the board provides all signals required for supplying the inductive transducers.
The primary circuit of the sensor is excited by means of a sinus generator.
The supply of the transducer is made through a differential power buffer.
The input level is generated parallely twice to optimise the clock frequency.
The circuit and secondary signals are simultaneously sampled through a
16-bit, 100 kHz stereo A/D converter (with AC specifications). The sampling
occurs synchronously with the exciting signal and at the extreme points to reach
the best precision.
9.2.1
Board calibration
The board is programmed with the following predefined parameters:
-
gain adjustment on primary and secondary circuit
-
Duty cycle is adjusted to 50 % at the delivery.
9.2.2
Board settings
The board
APCI-3701
is supplied with a predefined library of the sensor
properties and is programmed according to the connected sensor.
For each connected sensor, the following values are set:
-
frequency of the exciting signal in a range from 2 to 20 kHz
-
gain on the primary circuit between 0.7 V
rms
and 3.5 V
rms
-
gain on the secondary circuit between 1 and 20
-
load
-
phase of the return line signal for the supply voltage
