ACSG
8 STRAIN GAGE CHANNELS
FEATURES
z
8 differential analog inputs with AC/DC
coupling
z
Numerous gains available from 1 to 800
z
Wide dynamic range with variable shifts from
+/- 300% by steps of 15
z
Variable elliptic 8th order low-pass filter
adjustable from 20Hz to 5KHz
z
8 current supplies
I = 8,57mA ( 3V/350W)
I = 28,57mA ( 10V/350W)
z
8 continuous outputs for individual use
z
A product designed for harsh environment
DESCRIPTION
trademarks and logos are registered
The ACSG board allows complete conditioning of 8 strain gage. It integrates fully within the
concept of distributed ACCR racks built by ADAS.
Each channel features:
z
z
z
z
z
z
z
a test and measurement differential amplifier with selectable gains from 1 to 800
a high dynamic range allowing shifts of ± 300 %
a high-pass filter selectable or not
a variable elliptic 8 th order low-pass filter on the switched channel and/or the
continuous channel
Note: the filter cut-off frequency is adjustable using a potentiometer for all the
channels from 20Hz to 5KHz
switched outputs for local encoding
Continuous outputs filtered or not for individual use as part of a conditioning board
Current driving of 28.57mA ( 10V/350W) or 8.57mA ( 3V/350W).
9 rue Georges Besse – BP 47 – 78330 FONTENAY LE FLEURY – FRANCE
Tél.:(33) 1 30 58 90 09 - http://www.adas.fr - mail@adas.fr
ACSG
SPECIFICATIONS
TYPE
INPUTS
- Number
- Mode
- Level
- Impedance
- Coupling
AMPLIFIER
- Type
- Selectable gains
- Programming
- PGA output level
- Input offset instability
- Gain instability
- Common Mode Rejection
GAUGES
- Wiring
- Connection
- Bridge impedance
- Selection
- Injection current
- Compliance
- Current accuracy
- Regulation rate
- Short-circuit protection
- Offset
Fixed
Variable
SWITCHED CHANNELS FILTERING
- Type
- Order
- Polynomial
- Frequency range
- Control
- Rippling
- Attenuation
- Distortion + noise
CONTINUOUS CHANNELS FILTERING
(t = 25°C)
STRAIN GAGE CONDITIONER
8
Differential
+/- 2,5 V FS GT = 1
≥ 10 MΩ with power on
≥ 100 KΩ with power off
AC or DC using straps
Test and measurement
1 – 10 – 100 – 200 – 300 – 500 – 600 – 700 – 800 - GX
With switches
± 2,5 V FS offset = 0
2 m V/°C
20 ppm/°C
90 dB to 1 KHz
4 wires (2 x power supply – 2 x measurements)
Bridge
120Ω / 350Ω typical (1KΩ max.)
per channel
8.57mA (3V / 350Ω) or
28.57mA (10V / 350Ω)
10,.5V
≥± 0.2 %
≥ 1/1000
Yes
Selectable from 0 to ± 300 % of FS by steps of 15 %
Selectable from 0 to ± 15 % of FS by steps of 15 %
Switched capacitors
8, low-pass
Variable elliptic
20 Hz to 2 KHz
FCLK = 100 CF
± 0,15 dB from DC at 0.9 CF
≥ 70 dB at 2 x CF
≤ 70 dB
Switched channels filter selectable or not
SWITCHED OUTPUTS
- Level
- Impedance
- Linearity
- Accuracy
± 5V FS
≤ 10 Ω IOUT ≤ 5 mA
≥ 2 x 10 -4
≥± 3 x 10 -4 of FS at t = 25°C
≥± 0,3 % of FS from - 20°C to + 85°C
ACSG
CONTINUOUS OUTPUTS
- Number
- Level
- Accuracy
- Output impedance
- Signal image
- Channel bandwidth w/o filter
SIZE (H x L x D) in mm
8
± 2,5 V FS
≥± 0,5% of FS (0 < t < 60°C)
≤ 10 Ω for Iout ≤ 5mA
After conditioning and before or after filtering
≥ 5 KHz
114 x 78 x 18 for CI
88 x 17.6 for the FRONT panel
WEIGHT
135gr
POWER REQUIREMENT
+ 15 V / 50mA ; - 15 V / 50mA
+ 7, 5 V / 250mA ; - 7, 5 V / 250mA
CONNECTIVITY
FRONT panel : DMC.M. 2 x 20 pts
Back plane : AMP 501 Minibox - 80pts
ENVIRONMENT
- Storage temperature
- Operating temperature
- Specifications
- Relative humidity
- Sinusoidal vibrations
- Shocks
- Pressure
- Electromagnetic environment
EUROPEAN NORMS
- 55 + 100°C
- 40 + 75°C
- 10 + 60°C
90 % (with no condensation)
20 to 2000 Hz – 5G
100 g – 6 ms
25 to 1100 mbar
Standards: MIL STD 461A and 462
EMC - EN 61326 - EN 55011 Class A
CE Compliance
ROHS - 2002/95/EC
HOW TO ORDER?
ACSG
ACCESSORIES
5
24/46
GLOSSARY
B
A
MA
= Analog mass
IN (+), IN (-)
= Analogs inputs
SV X
= Continuous outputs channels
IAL X
= Excitation current
PIN
5
4
3
2
1
SV0
IAL0
IN (+) 0
IN (-) 0
MA
PIN
10
9
8
7
6
SIGNAL
SV1
IAL1
IN (+) 1
IN (-) 1
MA
PIN
15
14
13
12
11
SIGNAL
SV2
IAL2
IN (+) 2
IN (-) 2
MA
PIN
20
19
18
17
16
SIGNAL
SV3
IAL3
IN (+) 3
IN (-) 3
MA
PIN
5
4
3
2
1
SIGNAL
SV4
IAL 4
IN (+) 4
IN (-) 4
MA
PIN
10
9
8
7
6
SIGNAL
SV5
IAL5
IN (+) 5
IN (-) 5
MA
PIN
15
14
13
12
11
SIGNAL
SV6
IAL6
IN (+) 6
IN (-) 6
MA
PIN
20
19
18
17
16
SIGNAL
SV7
IAL7
IN (+) 7
IN (-) 7
MA
SIGNAL
TRACEABILITY FORM
DOCUMENT FOLLOW-UP
Title:
ACSG
Titre :
English documentation
(Document creation - Création du document)
Edition: 1
Written
by
D. PIMONT
on
Revised
by
B. THOUËNON
on
Ph. DUTIN
Approved by
on
Warning: Unless otherwise stated, this revision
overwrites the previous one which must be destroyed,
along with any copies given to your collaborators.
23/38
Visa
23/38
Visa
23/38
Visa
Avertissement : En l’absence d’indication contraire, cette nouvelle
édition annule et remplace l’édition précédente qui doit être détruite,
ainsi que les copies faites à vos collaborateurs.
Edition
Nature of the modifications (key words)
Written
Revised/Approved
Edition
Nature des évolutions (mots clés)
Rédigé
Revu/Approuvé
Modification du tableau des offsets fixes
2
3
4
by
D. PIMONT
by
B. TANG
on
24/03
on
24/03
Visa
Rev. A
Documentation update and english doc
creation
Advance in revison B of the board
Rev. B
Visa
by
D. PIMONT
by
B. TANG
on
24/15
on
24/15
Visa
Visa
DMC connector suppression in the
documentation
by
D. PIMONT
by
B. TANG
on
24/49
on
24/49
Rev. B
Visa
Visa
by
by
on
on
Visa
Visa
by
by
on
on
Visa
Visa
5
6
DOCUMENT ARCHIVED
DOCUMENT ARCHIVE
No
Yes
on
' ed. .. > @ = Document input/output (Entrée/sortie modification de la documentation)
# ed. .. > @ = Board new function input/output (Entrée/sortie nouvelle fonctionnalité du produit)
DSQ - 4.5.a - Indice F - 98/41
T.S.V.P.
ACSG - Rev. B - Edition 4 – 24/49
1
NOTES :
ACSG - Rev. B - Edition 4 – 24/49
2
ACSG
SUMMARY
Chapter A
Presentation......................................... 5
Chapter B
Operation.............................................. 6
B.1. Input Stage............................................................................... 6
B.2. Test and Measurement Amplifiers......................................... 7
B.3. Offset shift ............................................................................... 8
B.4. Filtering .................................................................................... 9
B.4.1. Determining cut-off frequency ...................................... 9
B.4.2. Filter response............................................................ 10
B.5. Switched-Channels Output Stage ....................................... 11
B.6
Continuous channels............................................................ 11
Chapitre C
Implementation .................................. 12
C.1. Installation ............................................................................. 12
C.2. Fitting the board in a box ..................................................... 12
C.3. Front panel connectivity....................................................... 12
C.4. Backplane connector............................................................ 13
C.5. Bridges................................................................................... 15
ACSG - Rev. B - Edition 4 – 24/49
3
C.6. Switches................................................................................. 16
C.6.1. Selecting port supply current...................................... 16
C.6.2. Input high-pass filter ................................................... 17
C.6.3. Test and measurement amplifier gains ...................... 18
C.6.4. Offset shift .................................................................. 19
C.6.5. Selecting output filter.................................................. 20
C.6.6. Switched channels outputs......................................... 20
C.7. Adjustement procedure........................................................ 21
C.7.1. Gain adjustment ......................................................... 21
C.7.2. Test and measurement amplifier offset ...................... 21
C.7.3. Bridge offset ............................................................... 21
C.7.4. Filter frequency........................................................... 22
Appendix
............................................................ 23
FIXED OFFSET TABLE .......................................................................... 23
CONFIGURATION LAYOUT.................................................................... 23
EQUIPMENT LAYOUT ........................................................................... 23
ACSG - Rev. B - Edition 4 – 24/49
4
Chapter A
Presentation
The ACSG gauge-bridge board can be used to condition bridged sensors.
It provides, for each of the eight channels, the following features:
Supplying current to the bridge,
Amplifying, and switching from differential mode to one-wire
mode,
Channel filtering,
Offset shift,
Continuous channels outputs
Switched channels outputs
The keys points of the product are:
High-tech development built around up-to-date devices
Adjustable low-pass filters requiring no version control
Simplified use of resources
Superior features
Simple and clear configuration resulting in time savings and
reduced error risks
Easy to implement
ACSG - Rev. B - Edition 4 – 24/49
5
Chapter B
Operation
B.1. Input Stage
The bridge is supplied with « current ».
The block diagram below shows the selected connection:
+ 15V
CURRENT
GENERATOR
Selection of 28,57mA
or 8,57mA
RF
4-wire bridge
C
IN (+)
BRIDGE
A
+
IN (-)
PGA
AA
C
RF
High-pass
Impedance is provided by two « A » amplifiers connected as a tracking
stage, which makes the input filter (1st order high-pass filter) independent
from any source impedance.
The bridges are driven by two currents:
28.57mA (10V/350ȍ)
8.57mA ( 3V/350ȍ)
Thus a short circuit on one channel does not impair other measurements.
Current driving prevents line loss errors occurring in the cables to the
bridge, “compliance” is 11V, i.e. line loss can be up to 1V.
Independent current generators for each channel feature accuracy values
compliant with the rest of the chain.
Sensitivity is the same as for the other products of the line (ex ACPJ).
ACSG - Rev. B - Edition 4 – 24/49
6
B.2. Test and Measurement Amplifiers
The bridge unbalance voltage is amplified by a test and measurement
amplifier with microswitch-selectable gain.
SX02
GAIN
1
10
' 50
100
200
300
500
600
700
800
' X
1
2
3
4
*
*
*
*
*
*
*
*
*
*
*
*
*
*
' VIN (r)
5
2,5
250
50
25
12,5
8,33
5
4,16
3,57
3,125
V
mV
mV
mV
mV
mV
mV
mV
mV
mV
*
* = ON
The position “6” is not used.
PX00
RG = RX 07 +
2
40 K:
RG =
G-1
- 50 :
' RG is factory-wired for a gain of 50.
Full-scale gains are given for encoding purposes, and a gain of “1” on
continuous channels (r 2,5 V FS).
ACSG - Rev. B - Edition 4 – 24/49
7
B.3. Offset shift
The offset can be very high, up to 300 % full scale.
Offset shift is performed at the summation point of the test and
measurement amplifier through a summing amplifier.
To achieve high offset-shifts while maintaining a good accuracy and a
stable performance, the offset shift can be broken down as follows:
Select shift direction:
positive or negative, with SX01-1
Select shift amplitude
This is done with switches SX01 – 2/3/4/5/6 according to the
table below.
For quicker results, we advise to use the “continuous’”
channel output on the front panel, the dynamic range of
which is sufficient to verify the total shift on the selected
channel.
A potentiometer on each channel enables to fine-tune the
shift within about ± 15 %.
Accordingly, seamless adjustments can be done from 0 through ± 300 %.
ACSG - Rev. B - Edition 4 – 24/49
8
B.4. Filtering
Signals from the test and measurement amplifiers are sent to 8th order
low-pass filters.
B.4.1.
Determining cut-off frequency
The cut-off frequency of the filters is adjustable with a multiturn
potentiometer located at the top of the board.
FCLK
Fc =
100
The TTL signal, FCLK, is to be seen at test points provded for this
purpose.
To obtain a high frequency dynamic range, the oscillator is provided with
a divider :N = 1; 10; 100
10 MHz
FCLK =
10 K:
x
N
Radj
Radj = 49,9 K: + Rpot
With Rpot
max = 500 K:
And N = 1 ; 10 ; 100
CF may vary from # 20 Hz to 20 KHz
The selected cut-off frequency is for all channels.
ACSG - Rev. B - Edition 4 – 24/49
9
B.4.2.
Filter response
The filter is a « switched capacitances » filter, i.e. with a 8th order low-pass
« elliptic variable » response.
- 20 dB to 1,2 Fc ; - 52 dB to 1,4 Fc ; - 70 dB to 2 Fc
Filter characteristics are given in the graphes below:
Frequency response
Phase response
One-step response
A lock system ensures excellent static performances with respect to
temperature.
ACSG - Rev. B - Edition 4 – 24/49
10
FLT 1069-1 - 8ème Ordre Elliptique Progressif
Temps de retard en fonction de la fréquence de la coupure
Fc = 200Hz
'x = 5,4ms
FLT 1069-1 - 8ème Ordre Elliptique Progressif
Temps de retard en fonction de la fréquence de la coupure
Fc = 2KHz
'x = 548µs
B.5. Switched-Channels Output Stage
For each channel, one amplifier with a gain of 2 provides the required
level for the measurement needs with the encoding board (r 5 V FS).
Switched channels are filtered with the 8th order low-pass filter.
B.6 Continuous channels
For the continuous channels, the user can select between “filter” or “no
filter” using S2 switches.
The full scale level is r 2.5 V FS.
ACSG - Rev. B - Edition 4 – 24/49
11
Chapitre C
Implementation
C.1. Installation
The user will beforehand read the following document:
GENERAL INSTRUCTIONS FOR
IMPLEMENTING ADAS PRODUCTS
INSTRUCTIONS GENERALES DE
MISE EN OEUVRE DES PRODUITS ADAS
C.2. Fitting the board in a box
An ACCR rack can accommodate 4 ACSG boards.
The ACSG board can be implemented with other analog ACHB ou ACTP
boards.
For restrictions with other boards, please refer to the user guide of the
ACCR rack.
The ACCR rack must be fitted with an ACAL rev. B
power supply to be able to support 4 ACSG boards
since these boards require high power on the + and –
7,5V
C.3. Front panel connectivity
The ACSG board uses a DMC 40-pt connector (2 x 20).
See datasheet of the product.
ACSG - Rev. B - Edition 4 – 24/49
12
C.4. Backplane connector
The ACSG board is fitted in an ACCR rack via a MINIBOX 80-pt AMP
connector.
Next page listing lists the signals used by the ACSG board.
ACSG - Rev. B - Edition 4 – 24/49
13
MINIBOX AMP 80pts MALE
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
SIGNAL
NC
0V ANA
PIN
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
V7
V6
V5
V4
V3
V2
V1
V0
0V ANA
- 15V
+15V
-7,5V
ACSG - Rev. B - Edition 4 – 24/49
14
SIGNAL
0V ANA
0V MES
0V ANA
- 15V
+ 15V
+ 7,5V
C.5. Bridges
The ACSG board supports bridged connections.
+ 15V
IOUT
+V
Current generator
RX 00
RX 01
'V
IN (-)
RX 03
-
RX 02
G
+
IN (+)
For non-used channels, IN(+) . IN(-) must be wired to
GND.
The non-used channels must be grounded to prevent
amplifiers saturation.
ACSG - Rev. B - Edition 4 – 24/49
15
C.6. Switches
C.6.1.
Selecting port supply current
S1
OFF = 28,57mA (10V/350ȍ)
ON
ON = 8,57mA ( 3V/350ȍ)
1
Channel 1
2
Channel 2
3
Channel 3
4
Channel 4
5
Channel 5
6
Channel 6
7
Channel 7
8
Channel 8
ACSG - Rev. B - Edition 4 – 24/49
16
C.6.2.
Input high-pass filter
SX00
AMPLI
VIN
+
1PF
R
Filter frequency depends on mains.
1
with
Fc =
2 S RC
For Fc = 0,25 Hz
and
Ÿ
C x 16 = 1 PF
C x 17 = 1 PF
RX04 = 640 K:
RX25 = 640 K:
In use with continuous channel:
ON
SX00 = ON
1
Ÿ
2
AC coupling:
ON
SX00 = OFF
1
2
Note: Make sure to switch both switches.
ACSG - Rev. B - Edition 4 – 24/49
17
C.6.3.
Test and measurement amplifier gains
Each channel features a 6-point switch.
GAINS
1
10
100
200
300
500
600
700
800
' X
SX02
2
3
1
4
5
6
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
= “ON” on selected position
'
= Arbitrary gain (to be defined on order)
>>>NOTE: The “6” is never used.
One of the gains is user-selectable on position 5 “ON”.
G=1+
40 K:
Ÿ RG =
40 K:
RG
for G = 50
RPX00 = 816 : -
G-1
Ÿ RG = 816 :
500 :
2
RPX00 resistor is on plots to enable wiring another value.
SX02
ON
6 = not used
1
2
3
4
5
6
Ex. : G = 600
ACSG - Rev. B - Edition 4 – 24/49
18
C.6.4.
Offset shift
The offset can be shift or varied up to +/- 300 %.
The diagram below shows the available options.
SX01
Shift
direction
Shift
Ȉ
2
3
4
5
6
SX01-1
OFF = Positive
ON = Negative
Shift direction
Potentiometer ± 15 %
Combined fixed offset 0 to 300 %
according to table
Variable offset
ǻ Ed. 3 [
SX01
ON
1
2
3
4
5
6
Ex : + 189 % (See table in appendix)
ǻ Ed. 3 ]
ACSG - Rev. B - Edition 4 – 24/49
19
C.6.5.
Selecting output filter
The ACSG board features, for each conditioned channel:
one continuous output
one switched output
After it has been amplified and offset-shifted, the bridge conditioned signal
is driven as follows:
G=2
A
Low-pass 8th order
filter
r 2,5V FS
W/o
T&M
amplifier
Switched
panel output
Minibox FdP
With
S2
G=1
Selecting with or w/o
filter on continous
channel
S3
r 2,5V FS
A
Continuous channel
output
DMC
FAV
Note: The switched channel is always filtered.
C.6.6.
Switched channels outputs
ACSG boards can be used alone in an ACCR rack.
The ACCR rack thus accommodates 4 x 8 = 32 gauge-bridge channels
ACSG - Rev. B - Edition 4 – 24/49
20
C.7. Adjustement procedure
C.7.1.
Gain adjustment
The test and measurement amplifier features a gain setting on position "5"
of SX02
The gain is factory-set with a value of 50.
This setting can be changed if required by changing RPX00.
(See chapter C.6.3. “Test and measurement amplifiers gains”).
C.7.2.
Test and measurement amplifier offset
Test and measurement amplifiers feature an offset setting. It avoids
changing the fine offset adjustment associated with the bridge offset when
changing the gain (PX02).
C.7.3.
Bridge offset
The connection used for ACSG boards enables to balance the initial
bridge offset from 0 to r 300 %.
- Select a fixed shift as close as possible to the decoding
- Adjust with the potentiometer of the channel located at the top of
the board
ACSG - Rev. B - Edition 4 – 24/49
21
C.7.4.
Filter frequency
Filter cut-off frequency is 100 FcK.
The adjustment dynamic range can be increased with the predivider:
1; 0; 100 provided in the oscillator.
TP1 = FCLK
+ GND
S3
= Frequency control
= Board ground
DIV
1
OFF
2
OFF
ON
OFF
OFF
ON
1
ON
ON
1
FcLK
CF
10
20 KHz to 250 KHz
200 Hz to 2,5 KHz
100
2 KHz to 25 KHz
20 Hz to 250 Hz
200 KHz to
2,5 MHz*
1
* The filter maximum bandwidth is 5 KHz
** Do not use this position
ACSG - Rev. B - Edition 4 – 24/49
22
2 KHz to 25 KHz*
NOT ALLOWED**
Appendix
FIXED OFFSET TABLE
CONFIGURATION LAYOUT
EQUIPMENT LAYOUT
ACSG - Rev. B - Edition 4 – 24/49
23
FIXED OFFSETS TABLE
SX01
ON
Ex : + 203 %
S1
1
S6
2
S5
3
4
5
= ON = Negative shift
= OFF = Positive shift
6
S4
S3
S2
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
VARIATION
IN %
0
9
20
29
43
52 *
63
72
75
84
95
104
118
127
138
147
137
146
157
166
180
189
200
209
212
221
232
241
255
264
275
284
The table above is given for a variable shift of zero.
A variable shift of ± 15 % will be added algebrically to the fixed setting.
Example: Fixed shift: 52 % + variable shift ± 15 %
i.e. a setting of 37 % to 67 %
ACSG - Rev. B - Edition 4 – 24/49
24