Baumer BA DACU 820 - Handbuch (Seite 14)

DACU_820_BA_V2_1M.doc 27/40 Baumer Electric AG
Frauenfeld, Switzerland
5.3.2 Variable range
With the variable range, the measuring chain can be adjusted for any output signal with a known
measured magnitude. Select the suitable measurement range according to the charge to be
expected. Now put the system into operation and set the output signal to the desired voltage value
using the range potentiometer.
To do this, the lid of the charge amplifier must be opened.
Range
L0
L1
Arrangement of potentiometer and DIP-switches
Example:
The measuring chain should be adjusted for a maximum force to an output voltage of 8V
Charge of sensor for maximum force: 500.000pC.
Input Range A1 and A0 (Pin 7 and 8) set on high (with pos. Logic)
Put the system into operation and set the output signal to 8V using the range potentiometer for
maximum force.
Important note:
The charge amplifier has to be in operational mode for five minutes after adjustment of the
variable range. After this time the setting is stored in the non-volatile memory.
O N
1 2 3 4
DACU_820_BA_V2_1M.doc 28/40 Baumer Electric AG
Frauenfeld, Switzerland
5.4 Alarm outputs
The two alarm outputs monitor the output signal of channel 1, and can be used to signal limits or to
define measurement windows. The threshold voltage of 0 – 10V can be set in two ways:
3. The threshold voltage is fed in externally via the input on pin 3 or 4
or
4. It is set after the lid is opened, using the two potentiometers L0 and L1 (see Fig. 5.3.2). The set
voltage can be measured on pin 3 or 4.
Both alarm outputs close the contact as soon as the set threshold value is exceeded, and remain set
until the next reset.
Channel selection:
Both alarm outputs can be assigned to one of the two analog outputs (CH1, CH2) by a DIP-switch:
DIP 3 DIP 4
ON TH 1 CH1 TH 2 CH 1
OFF TH 1 CH 2 TH 2 CH 2
Comment:
Two Photo-Mos relays are used as circuit elements. The outputs are galvanically separated and
suitable for AC and DC. However, they are not short-circuit-proof and must not be operated beyond the
specification. However, the Photo-Mos relays can be replaced quickly in the case of a defect
(socketed).
5.5 RESET function
Because of the finite insulation resistances of the sensors, cables and electronic components, part of
the charge which the sensor outputs is lost. This means that with a constant physical measured
magnitude (e.g. force), the output signal changes in the positive or negative direction. Because of this
"drift“, static measurements can only be carried out to a limited extent or over short periods. It is
therefore necessary to reset the charge amplifier cyclically.
The charge amplifier is switched active via the Operate input.
Comment:
The charge amplifier should always be switched to "Reset“ if no measurement result is required.
5.6 PEAK function
For the duration of one measurement cycle, the peak function supplies the maximum value of the
output signal of Channel 1. It is reset automatically using the control input Operate.
t
t
Operate
+10V
1
0
-10V Signal out CH1
Peak out