LS A2C-SG2-M12 User manual

Page 1 of 44
Dual strain gauge amplifier
with CAN bus
Features
 Complete strain gauge signal conditioning
 Programable analogue gain
 Differential analogue frontend
 Selectable excitation voltage 2.5V / 5V
 Up to 4800 samples per second
 24-bit ADC
 Periodic CAN messages with programmable data types
 32 taps user programable FIR filter
 Low power consumption
 Durable aluminum / stainless steel housing
 Software upgradable via CAN bus
 Signal to noise ratio calculation
General Description
The A2C-SG2-M12 Strain gauge amplifier uses state of the art digital and analogue components to achieve exceptional
sensitivity and high band width.
Specifications
 Selectable 2.5V / 5V Strain gauge supply
 11-30V supply voltage
 70mA supply current
 CAN interface (2.0A & B)
 CAN driver ISO 11898 compatible
 Logic output (versions made to order)
 Standard industrial M12 connector
 CNC machined aluminum / stainless steel housing
A2C
-
SG2
-
M12

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Dual strain gauge amplifier
with CAN bus
1 Ordering information
Part Number
Package
Interface
CAN Bus
Logic Output
A2C
-
SG
2
-
M12
-
A
Black
a
nodized
aluminum
M12, 5pin Male
connector
for
CAN Bus
2 x M12, 5pin Female for strain
gauges
Yes
No
A2C
-
SG
2
-
M12
-
S
Stainless steel 316
M12, 5pin Male connector
for
CAN Bus
2 x M12, 5pin Female for strain
gauges
Yes
No
For a customer specific package please contact us. We have other materials / coatings available not listed here.

Page 3 of 44
Dual strain gauge amplifier
with CAN bus
Specifications for
A2C-SG2-M12 Dual strain gauge amplifier to CAN bus
Version 1.11
30/07 2021

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Document tracking control
VERSION
SECTION
CHANGED BY
DATE
CHANGE
1.00
1.01
1.02
1.03
1.04
1.05
1.06
1.07
1.08
1.09
1.10
1.11
All
All
9
All
All
17.1.1
12
2
12
All
2
All
All
JL
JL
JL
JL
JL
WN
JL
JL
WN
JL
JL
JL
0
3
-
0
8
-
201
3
12-02-2014
01-02-2015
26-06-2015
12-05-2017
15-01-2018
17-01-2019
19-03-2019
20-03-2019
20-07-2019
07-07-2020
29-07-2021
Initial Version
Updated error codes, baud rate, added SNR
Added periodic messages follow ADC. Released for
public viewing
Added Integer Scalling section, Corrected CAN follow
ADC wrong values for ints and floats
New commands for periodic messages from firmware
0x0107 and onwards. New examples.
Corrected wrong value to reset factory settings.
Added more examples of float to byte array for
calibration. Added data to specifications
Corrected float to array error
Gramma and typo corrections
Removed old A2C-SG drawing
Added FIR Filter and SNR sections
Corrected custom baud-rate calculations
Added command for default calibration values
Added section From measurement to CAN Value
Updated mechanical drawing

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Contents
1 Ordering information .......................................................................................................................................................................2
Document tracking control .......................................................................................................................................................................4
2 Specifications ..................................................................................................................................................................................7
2.1 Functional block diagram .....................................................................................................................................................8
............................................................................................................................................................................................................8
2.2 ADC performance .................................................................................................................................................................9
2.2.1 RMS noise (nV) vs. Gain and data rate ...........................................................................................................................9
2.2.2 Effective resolution ..........................................................................................................................................................9
2.3 Conformity ............................................................................................................................................................................9
2.4 Strain gauge pin outs .........................................................................................................................................................10
3 Mechanical Drawing......................................................................................................................................................................10
3.1 Mounting .............................................................................................................................................................................10
4 Programming tools ........................................................................................................................................................................11
5 Getting Started ..............................................................................................................................................................................12
5.1 Trouble shooting connection ..............................................................................................................................................15
6 Protocol .........................................................................................................................................................................................16
6.1 Protocol format ...................................................................................................................................................................16
7 Initial Setup ...................................................................................................................................................................................17
7.1 CAN Identifier .....................................................................................................................................................................17
7.1.1 Command: Set CAN ID .................................................................................................................................................17
7.1.2 Command: Get Standard CAN ID .................................................................................................................................17
7.2 Baud rate ............................................................................................................................................................................17
7.2.1 Command: Set baud rate ..............................................................................................................................................17
7.2.2 Command: Get baud rate ..............................................................................................................................................18
7.3 Custom baud rate ...............................................................................................................................................................18
7.3.1 Command: Set custom baud rate ..................................................................................................................................18
7.3.2 Command: Get custom baud rate .................................................................................................................................19
7.4 CAN Filters .........................................................................................................................................................................19
7.4.1 Command: Set CAN Filters ...........................................................................................................................................19
7.4.2 Command: Get CAN Filters ...........................................................................................................................................20
8 ADC setup.....................................................................................................................................................................................21
8.1 Bipolar / Unipoloar configuration ........................................................................................................................................21
9 From Measurement to CAN value ................................................................................................................................................22
9.1.1 Command: Setup ADC ..................................................................................................................................................23
9.1.2 Get ADC mode ..............................................................................................................................................................24
9.1.3 A note on data rate and data requested ........................................................................................................................24
10 Excitation voltage selection setup ............................................................................................................................................25
10.1.1 Set excitation voltage:...............................................................................................................................................25
10.1.2 Get excitation voltage: ..............................................................................................................................................25
11 Setting up FIR filter ...................................................................................................................................................................26
11.1.1 Command: Set FIR parameters ................................................................................................................................26
11.1.2 Command: Set FIR Coefficients ...............................................................................................................................26
11.1.3 Command: Get FIR parameters ...............................................................................................................................27

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11.1.4 Command: Get FIR Coefficients ...............................................................................................................................27
11.2 Using the A2C-Sensor Utility ..............................................................................................................................................28
11.3 Using MATLAB ...................................................................................................................................................................28
12 Getting measurement values....................................................................................................................................................29
12.1.1 Command: Get both .................................................................................................................................................29
12.1.2 Command: Get configurable channel measurements ..............................................................................................29
12.1.3 Command: Get current channel measurements with math functions .......................................................................30
12.1.4 Command: Reset Global Minimum, Maximum and Mean values .............................................................................30
12.1.5 Command: Set Integer Scaling .................................................................................................................................30
12.1.6 Command: Get Integer Scaling ................................................................................................................................31
12.1.7 Command: Set CAN timeout ....................................................................................................................................31
12.1.8 Command: Get CAN timeout ....................................................................................................................................31
12.1.9 Command: Set wait period between CAN messages ...............................................................................................31
12.1.10 Command: Get wait period between CAN messages ..............................................................................................32
13 Setting up Periodic Messages ..................................................................................................................................................33
13.1.1 Command: Set Periodic Messages ..........................................................................................................................33
13.1.2 Command: Set Periodic Messages Follow ADC ......................................................................................................34
13.2 J1939 type CAN Messages (only for 2 active channels) ....................................................................................................34
13.2.1 Command: Set Periodic Messages to follow ADC - J1939 style ..............................................................................34
13.2.2 Command: Get Periodic Messages to follow ADC - J1939 style ..............................................................................35
14 Signal to Noise calculations......................................................................................................................................................35
14.1.1 Command: Set SNR sample numbers ......................................................................................................................35
15 Calibrating ................................................................................................................................................................................36
15.1.1 Command: Calibrate input channels using floating point data ..................................................................................36
15.1.2 Command: Calibrate input channels using integer data (signed 32bit integer) ........................................................37
16 Set Default Calibration Values..................................................................................................................................................37
16.1.1 Command: Set Default Calibration Constants ..........................................................................................................37
17 Save Current Calibration Constants .........................................................................................................................................37
17.1.1 Command: Save Current Calibration Constants .......................................................................................................37
18 Getting Sensor Information.......................................................................................................................................................38
18.1.1 Command: Get sensor information ...........................................................................................................................38
19 Save Current Parameters in Sensor.........................................................................................................................................39
20 Reset to Factory Settings .........................................................................................................................................................39
20.1.1 Command: Set factory settings.................................................................................................................................39
21 Recommended settings to get started ......................................................................................................................................40
22 Updating Sensor Firmware .......................................................................................................................................................41
23 Error Codes ..............................................................................................................................................................................42
23.1.1 Command: Not Acknowledged .................................................................................................................................42
23.2 Error message list: .............................................................................................................................................................42

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2 Specifications
Parameter
Condition
Values
Unit
SUPPLY
VOLTAGE
Operating Voltage (Vin)
Supply Current
Power consumption
Turn-On Time
Vin = 24V
Vin = 24V
Min
11
Typical
22
0.53
1500
Max
32 V
mA
W
ms
STRAIN GAUGE INPUTS
Number of input channels
Programmable gain
Data rate
Bandwidth (-3dB)
Resolution
RMS noise
Differential input voltage range (Bipolar setup)
Analog input current
Input current drift
Excitation voltage 5V
Excitation voltage 2.5V
Excitation current – all excitation voltages
Recommended strain gauge impedance (5V)
Recommended strain gauge impedance (2.5V)
1
0.3
4.95
2.475
2 x differential
24
8.5
±Excitation
voltage/gain
±3
5
2.5
350
150
128
4800
1445
5.05
2.525
150
Hz
Hz
bits
nV
V
nA
pA/°C
V
V
mA
Ω
Ω
NPN
OUTPUT
Maximum Collector Emitter Voltage
Maximum continuous current
40
75
V
mA
CAN BUS 2.0A & B
Transceiver delay loop time
Baud rate
Default device standard ID
Default device filters
Software Protocol
Hardware Protocol
10
0x125
0x3E8-0x3EB
Proprietary
2.0A / 2.0B
150
1000
ns
kBits/sec
HOUSING
Housing Body Material –A suffix
Housing Body Material –S suffix
Lid Material - A suffix
Lid Material - S suffix
Black anodized Aluminum
Stainless steel 316
Black anodized aluminum
Stainless steel 316
CONNECTIVITY
Pin 1 = Shield
Pin 2 = Vin
Pin 3= Ground (both power and CAN ground)
Pin 4= CAN High
Pin 5 = CAN Low
M12
-
A Male 5 pin
Connector
INPUTS x 2
Pin 1 = Negative Input
Pin 2 = Positive Input
Pin 3= Positive Excitation
Pin 4= Negative Excitation
Pin 5 = Shield
M12-A Female 5
pin Connector
DIMENSIONS
(Including base plate)
Length
Width
Height
Weight
Min
80.2
59.6
26.2
Typical
80.6
60
27
190
Max
81
60.4
27.8
mm
mm
mm
gram
TEMPERATURE
Operating Temperature Range
Housing temperature rise
-20
3
65 Deg
Deg

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2.1 Functional block diagram

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2.2 ADC performance
2.2.1 RMS noise (nV) vs. Gain and data rate
Data Rate
Filter value
Output data
rate [Hz]
Settling time
[ms] Gain=1 Gain=8 Gain=16 Gain=32 Gain=64 Gain=128
1023
4.7
639.4
270
42
23
13.5
10.5
9
640 7.5 400 320 50 27 17 13 11.5
480
10
300
350
60
35
19
15
12.5
96 50 60 1000 134 86 50 35 29
80
60
50
1050
145
95
55
40
32
32 150 20 1500 225 130 80 58 50
16
300
10
1950
308
175
110
83
73
5 960 3.125 4000 590 330 200 150 133
2
2400
1.25
56,600
7000
3500
1800
900
490
1 4800 0.625 442,000 55,000 28,000 14,000 7000 3450
2.2.2 Effective resolution
Data Rate
Filter
value
Output data
rate
[Hz]
Settling time
[ms]
Gain=1
Gain=8
Gain=16
Gain=32
Gain=64
Gain=128
1023 4.7 639.4 24 24 24 24 24 23
640
7.5
400
24
24
24
24
23.5
22.5
480 10 300 24 24 24 24 23.5 22.5
96
50
60
23.5
23
23
22.5
22
21.5
80 60 50 23 23 22.5 22.5 22 21
32
150
20
22.5
22.5
22
22
21.5
20.5
16 300 10 22.5 22 22 21.5 21 20
5
960
3.125
21.5
21
21
20.5
20
19
2 2400 1.25 17.5 17.5 17.5 17.5 17.5 17.5
1
4800
0.625
14.5
14.5
14.5
14.5
14.5
14.5
2.3 Conformity
IEC 60721
-
3
-
5
Climate
Biological
Chemically active substances
Mechanically active substances
Contaminating fluids
Mechanical conditions
Tests are ongoing

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2.4 Strain gauge pin outs
Please refer to the marking on the A2C-SG2 for how to connect it.
3 Mechanical Drawing
3.1 Mounting
Mount the sensor on an even surface. Use up to 4x M4 bolts to secure the sensor from the top or the bottom