Baumer BA DACU 820 - Handbuch (Seite 13)

DACU_820_BA_V2_1M.doc 25/40 Baumer Electric AG
Frauenfeld, Switzerland
4.3 Measuring ranges
Choice of measuring range
Range CH1 measuring range
A1 A0 pC/10V
1 0 0 500’000
2 0 1 200’000
3 1 0 100’000
4 1 1 100’000...500’000
Range CH2
B1 B0
5 0 0 20’000
6 0 1 10’000
7 1 0 5’000
8 1 1 2’000
5 Start up
5.1 Connection on controller side
The inputs and outputs are galvanically separated and can be connected as both positive and negative
logic. The inputs have the common connection on pin 19 – Com Logic Input. The two outputs are on
pin 25 – Com Logic Output.
Examples of the Operate Signal:
DACU
D
-S
u
b
machine controller
S V s 20 Operate
19 Com Logic Input
positive logic, operate aktiv with closed switch S
DACU
D
-S
u
b
machine
controller
S
V s
20 Operate
19 Com Logic Input
negative logic, operate active with closed switch S
Note:
If no change of charge range has to take place during operation, the required range inputs can be
permanently connected to the supply voltage. The Com Logic Input is then connected to the Supply
GND.
5.2 Connecting on sensor side
To connect a sensor, high-insulation cables must always be used. If possible, short-circuit the sensor
before connecting it, because piezo-electric sensors can generate high voltages, which could damage
the electronics of the charge amplifier. Avoid touching the insulation of the BNC plug, and ensure that
no dust or humidity can penetrate it. Humidity and other contamination reduce the insulation, and can
cause increased drift.
DACU_820_BA_V2_1M.doc 26/40 Baumer Electric AG
Frauenfeld, Switzerland
5.3 Setting the measurement ranges
The measurement ranges are selected via the four range inputs (for connection see Section 5.1
Connecting on controller side).
5.3.1 Fix ranges
3 fix ranges from 100’000pC to 500,000pC for channel 1 and 4 fix ranges from 2’000pC to 20’000pC
for channel 2 are available. Select the suitable measurement range according to the expected
charge.
Example:
The intention is to measure a clamping force using a piezo-electric strain sensor.
-Sensor sensitivity: -920pC/
µε
-max. clamping force 400kN strain on the measuring spot: 180 µε
The maximum charge is calculated as: pC
pC
Q 165600 180 920
max
− = ∗ − = µε
µε
chosen measurement range (-) 200.000pC/10V
Set Range A0 (Pin 8) input to high (with positive logic)
Output voltage at 400kN: V V
pC
pC
U
CH
28 . 8 10
200000
165600
1
= ∗
−
−
=
Comment
The other range input A1 must not be connected!
The maximum specified force for the mold protection is 0.5% = 2
die strain will have a value of 0.9 µε (0.5% of 180 µε )
The sensor has an output signal of: pC
pC
Q
S
828 9 . 0 920 − = ∗ − = µε
µε
choose measuring range: 2.000pC/10V
Input Range B1 und B0 (Pin 5 und 6) set on high (with pos. Logic)
the level for the mold protection should be set as follows:
V V
pC
pC
U
CH
14 . 4 10
2000
828
2
= ∗
−
−
=