A
GENERAL
A.1
INTRODUCTION AND SPECIFICATION
The model DAS 72.1 Mark III is a high precision, high speed digital amplifier for weighing and force
measurements with strain gauge (SG) sensors. The device can be controlled either by the front keys or via RS
485 port. 3 Logic inputs and outputs make complex control functions easy. The 3 logic outputs can be controlled
external too.
With the available as standard analogue output 4…20 mA the DAS 72.1 fulfills industrial requirements. The
device features full multi-drop communications capability and can be programmed via a straightforward ASCII
command set. The LDU xx.x series and the amplifier DAS 72.1 with on-board digital display, use the same
command set. You can connect up to 32 SG amplifiers of either the LDU XX.X series or DAS 72.1 type onto a
single RS485 bus.
The DAS 72.1 with its high precision 18-bit A to D converter and internal sample rate of up to 2400 measure-
ments / second, is particularly suitable for high dynamic measurements and control purposes.
Page 2
Manual DAS 72.1
Linearity
< 0.002 %
Excitation
5 V DC, load cells 80-2000 Ohm, 6 wire technique
Analogue input range
±3.2 mV/V (bipolar, for weighing applications and force measurements)
Minimum input per vsi
0.05
μ
V / d
Resolution
Internal ±260000 counts, ±18-Bit-A/D convertor; display max. ±99999 counts
Conversion rate
Internal 2400 measurements per second; external up to 600 measurements per second
Digital filter
FIR Filter 2.5 ... 19.7 Hz or IIR Filter 0.25 ... 18 Hz; programmable in 8 steps each
Calibration
Software calibration and set up
Computer interface
RS485 or RS422, full duplex, 9600 ... 115200 Baud; bus capability up to 32 devices
(RS485)
Weighing functions
zero, gross, tare, net, filter etc.
Analogue output
0/4...20 mA, 14-Bit resolution
Display
10.2 mm LED, green, 5 digits, 3 status LED for nett/motion/sign,
6 status LED for logic inputs and outputs
Logic inputs
3 opto-isolated inputs, 10 ... 30 V DC, max. 3.5 mA
Logic outputs
3 opto-isolated outputs, < 45 V DC / AC, 1 A
Temperature effects
on zero
5 ppm/°K typ.; max. <10 ppm/°K
on span
4 ppm/°K typ.; max. <8 ppm/°K
Temperature range
–10 °C to +50 °C (operating); –20 °C to +60 °C (storage)
Enclosure
tinned steel enclosure, protection IP 40; for 35 mm DIN-rail mounting.
Special housing IP 65 on request.
Dimensions
135 x 66 x 19 mm, weight ca. 180 g
Power supply
11 ... 25 V DC ±10 %, < 3 W, galvanically isolated
EMC
CE 73/23/EEC; 93/98/EEC and 89/336/EEC
All dimensions in mm. Dimensions and specifications are subject to change without notice.
DAS 72.1 Mark II / III Specifications
