Description
This board has 7 analogue inputs. Each of the inputs can be programmed for
an input range of 10mV, 40mV, 200mV or 2V full scale. The inputs are bipolar,
both positive and negative voltages can be measured. The inputs are
differential, the common-mode rejection is better than 60dB (1000x).
Each of the channels is calibrated individually. The accuracy is 0.5%. The
zero drift is compensated electronically and is neglectable over the temperature
range.
The input signal is digitized with an integrating A-D converter. 50Hz noise
is practically completely filtered. Pulse shaped noise on the input gives an
error in the reading that is determined by the energy content of the pulse, not
the amplitude. This results in very stable readings.
Each channel has a jumper that places a resistor of 100 Ohm 0.1%, parallel to
the input terminals. This is used for 0...20mA or 4...20mA signals.
The board has 7 LED's. The LED's flash when a channel is read and the input
voltage is more than 20% of full scale. After installation, the LED's must be
switched off since they influence the boards accuracy.
Specifications
|
width
|
4 TE
|
|
power supply
|
+/-15Vdc, < 40mA (LED's off)
|
|
input type
|
bipolar, differential
|
|
input range
|
10mV, 40mV, 200mV, 2V full scale
|
|
input impedance
|
500 kOhm (100 Ohm)
|
|
common-mode rejection
|
> 60dB (1000x)
|
|
common-mode voltage
|
max. 25V
|
|
jumpers
|
input resistance, board address
|
|
initial error
|
0.5% max.
|
|
temperature range operating
|
-10...+50°C
|
|
temperature range storage
|
-20...+70°C
|
|
temperature drift range
|
< 25 ppm / °C
|
|
temperature drift zero
|
< 0.05% of full scale
|
|
resolution
|
20.000 counts (0.5µV, 2µV, 10µV, 100µV)
|
|
A/D converter
|
integrating, integration period 20ms
|
Connections
|
pin
|
signal
|
jumper settings
|
|
1
|
0V
|

|
|
2
|
0V
|
|
3
|
- channel 7
|
|
4
|
+ channel 7
|
|
5
|
- channel 6
|
|
6
|
+ channel 6
|
|
7
|
- channel 5
|
|
8
|
+ channel 5
|
option jumpers
|
|
9
|
- channel 4
|

|
|
10
|
+ channel 4
|
|
11
|
- channel 3
|
|
12
|
+ channel 3
|
|
13
|
- channel 2
|
|
14
|
+ channel 2
|
|
15
|
- channel 1
|
|
16
|
+ channel 1
|