LEM BEN 5000 Use and care manual

9200-14 REV. E 11 September 2002
BEN 5000
DFR Calibration
Primary Training

Calibration Primary Training
Contacting us:
LEM Instruments, Inc.
23822 HAWTHORNE BLVD., SUITE 100
TORRANCE, CA 90505
TEL: [phone]
FAX: [phone]
Specifications and contents of this manual are subject to change.
COPYRIGHT 2002
LEM Instruments, Inc.
No unauthorized reproduction or duplication of this document is allowed without the express
consent of LEM.
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Table of Contents
1 INTRODUCTION.....................................................................................................................................4
2 GENERAL FUNCTIONS ........................................................................................................................6
2.1 OPERATING MODE : ...................................................................................................................................6
2.1.1 12 bit-analog/digital conversion of analog channels .....................................................................6
2.1.2 Anti-aliasing filter...........................................................................................................................6
2.1.3 Switchable RMS/DC conversion of the analog inputs (-02, -12, -22 option) .................................6
2.1.4 Transmission of the results to the processing unit by high speed serial line..................................6
2.2 CALIBRATION MODE: ................................................................................................................................7
2.2.1 Automatic calibration: offset and gain adjustment ........................................................................7
2.2.2 Self-test ...........................................................................................................................................7
3 CALIBRATION........................................................................................................................................7
3.1 STARTING AUTOCAL SOFTWARE : .........................................................................................................7
3.2 AUTO CONFIG MENU ................................................................................................................................9
3.2.1 Digital inputs window.....................................................................................................................9
3.2.2 Analog inputs window ..................................................................................................................10
3.2.3 Input ranges..................................................................................................................................11
3.2.4 Setting input ranges......................................................................................................................11
3.3 CALIBRATE MENU ...................................................................................................................................12
3.3.1 Selection of the channels to be calibrated ....................................................................................12
3.3.2 Offset calibration..........................................................................................................................13
3.3.3 Gain calibration ...........................................................................................................................13
3.3.4 Notes.............................................................................................................................................15
3.3.5 End of calibration.........................................................................................................................17
3.4 MEASURE MENU......................................................................................................................................18
4 APPENDIX 1 : HOW TO HANDLE INPUT TERMINALS FOR CALIBRATION .......................19
4.1 CALIBRATION OF ONE VOLTAGE INPUT.....................................................................................................19
4.1.1 Calibrate one voltage input with interruptible terminals (RTK/S, MTK P/P,...)..........................20
4.1.2 Calibrate one voltage input without interruptible terminals (SSK110, UK4,...) ..........................22
4.2 CALIBRATION OF ONE CURRENT INPUT....................................................................................................25
4.2.1 Calibrate one current input with interruptible terminals (RTK/S, MTK P/P,...)..........................26
4.2.2 Calibrate one current input without interruptible terminals (SSK110, UK4,...) ..........................29
5 APPENDIX 2 : DESCRIPTION OF TERMINAL MARKING .........................................................31
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1 INTRODUCTION
The BEN DFR is calibrated through a PC connected in turn to each Acquisition
Controller board. The PC runs the program ‘Autocal’, and walks the user through the
range settings & calibration for each analog channel. The calibration does not require
the user to manually adjust potentiometers, each board has electronically adjusted
trimpots, under the control of the calibration program. These values are read & stored
in the nonvolatile memory of the DFR.
The following is excerpted from the BEN 5000 Technical Reference Manual.
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623-XX
Acquisition card
This card is available in two different versions:
623-01, -11, -21 standard version
623-02, -12, -22 software switchable RMS/DC conversion
SENS 623
C
onnector
for PSU input
L
E
D
C
onnector
(to m ax thr ee
SENS 421 )
1
1
P5
P1
P2
P3
P4
DB9 connector
R
S232 to P
C
for calib ration
C
onnector
(to SENS 626 or
SENS 50 45 fiberop tic)
PSU in put
(o p ti o n )
C
onn ector
(to m ax tw o
SENS 422)
1
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Calibration Primary Training
2 GENERAL FUNCTIONS
The acquisition card can process 8 analog channels and 24 digital channels. It can
handle 2 different acquisition rates. Each analog channel is programmed for one of
those 2 rates. A yellow LED at the front edge of the card blinks twice per second
during normal operation mode.
The main functions of the 623 card are as follows:
2.1 Operating mode :
2.1.1 12 bit-analog/digital conversion of analog channels
The 623 card contains two 12 bit-analog/digital converters with 4 inputs fitted with
an independent and synchronous sample-and-hold per channel.
2.1.2 Anti-aliasing filter
The anti-aliasing filter (6th order BUTTERWORTH low-pass filter) attenuates the
components of the signal whose the frequency exceeds 0.35 times the sampling
frequency.
2.1.3 Switchable RMS/DC conversion of the analog inputs (-02, -12, -22
option)
An optional RMS/DC converter can be mounted on each channel, and is used for
measurements of AC signals at a low recording speed. It can be switched ON or OFF
for each channel independently, through the BENCFG software.
2.1.4 Transmission of the results to the processing unit by high speed serial
line.
The results of the conversion of the 8 analog channels and the status of the 24 digital
channels are sent to the processing unit through a synchronous line at 3 Mbits per
second.
The same transmission line is also used by the CPU for initializing and controlling
the correct operation of the card, at the connection time and each time that it switches
from the IDLE to the RUN mode.
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2.2 Calibration mode:
2.2.1 Automatic calibration: offset and gain adjustment
The card contains solid-state potentiometers for offset and gain adjustments which
allows compensation for component tolerance variance. These adjustments are made
by the user, by means of the calibration software.
2.2.2 Self-test
The self test procedure allows you to quickly check the correct operation of the
RMS/DC converter, the anti-aliasing filter, the A/D converters, and the gain and
offset potentiometers. It also checks for the presence of RMS/DC converters, and
digital isolation cards, 421. This procedure is automatically carried out when the
AUTO CONFIG menu (displayed at program startup) is selected.
3 CALIBRATION
NOTE: It is implied in the following sections that the user has taken appropriate steps
to isolate the DFR inputs from the field wiring. i.e. opening knifeblades, Phoenix
knives, etc.
3.1 Starting AUTOCAL Software :
Supplied with the BEN 5000, is a diskette containing the AUTOCAL program. This
is a DOS program, and functions most reliably when you shutdown Windows to DOS
mode. Also shipped with every BEN, is a serial communication cable labeled for
calibration use. It is a standard serial data cable.
To use the calibration function, you need an RS-232 connection cable, equipped with
a female DB-25 at the PC side, and a male DB-9 at the other. You will also use a PC
running the 'AUTOCAL' software.
Cable to use :
Card side : DB9 male PC side : DB25 female
Pin 2 →Pin 3
Pin 3 →Pin 2
Pin 5 →Pin 7
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Copy the AUTOCAL program files to your computer, using Windows explorer, or
via the DOS Copy command. We recommend that you create an independent
subdirectory to contain the AUTOCAL program:
C:\BEN32\AUTOCAL
Observe the following procedure :
• Connect RS-232 port of the computer to acquisition card connector P5.
• From the DOS prompt, in the directory containing "Autocal" software, run
AUTOCAL
• The AUTO CONFIG window appears on the screen after a few seconds.
NOTES :
− When serial Port 2 (COM2) of the PC is used, start the program with option 2:
AUTOCAL 2.
− When the 'AUTOCAL' program is running, the calibration software takes control of
the card and interrupts the dialogue with the processing, unit causing a temporary
error to be reported on the BEN.
• Press 'ENTER' to go to the main menu.
The main software menu is shown as follows:
Auto Config Calibrate Measure Debug Exit ?
The horizontal arrows allow you to move from one menu to another and the
<ENTER> key is used to accept your choice.
◊ The AUTOCONFIG menu allows you to select the input voltage and current
ranges, and to check the functionality of the hardware (Self Test).
◊ The CALIBRATE menu allows you to adjust gain and offset for each of the 8
channels.
◊ The MEASURE menu gives you access to a window in which you can display in
real time the value of the 8 analog inputs and the 24 digital inputs.
◊ The DEBUG menu is reserved for factory use.
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◊ The EXIT menu allows for quitting the software and returning to the DOS
prompt.
◊ The ? menu shows the 'AUTOCAL' software version.
The menus 'AUTOCONFIG' , 'CALIBRATE' and 'MEASURE' are described in the
following sections.
3.2 Auto Config Menu
Place the cursor on the AUTOCONFIG menu and select with the <ENTER> key.
The screen following screen appears:
AutoConfig Calibrate Measure Debug Exit ?
Line states
Digital inputs
Analog inputs
+1 : ----
+2 : ----
+3 : ----
+4 : ----
+5 : ----
+6 : ----
+7 : ----
+8 : ----
+ 9 : ----
+10 : ----
+11 : ----
+12 : ----
+13 : ----
+14 : ----
+15 : ----
+16 : ----
+17 : ----
+18 : ----
+19 : ----
+20 : ----
+21 : ----
+22 : ----
+23 : ----
+24 : ----
Pol Pol Pol Pol Pol Pol
State of hardware
Range
11A1
11A2
11A3
11A4
11A5
11A6
11A7
11A8
2V
2V
2V
2V
2V
2V
2V
2V
Shunts
Ω
Ω
Ω
Offset
256
256
256
256
256
256
256
256
Gain
256
256
256
256
256
256
256
256
RMS MF6 RMS Offset Gain
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Ω
Ω
Ω
Ω
Ω
NO
NO
NO
NO
NO
NO
NO
NO
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK Firmware revision index : 0
Fields to be modified by user
3.2.1 Digital inputs window
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This window gives you the status of the 24 digital inputs connected to this acquisition
controller. It uses the following conventions :
• Channel status
--- = channel not available (no 421 board connected)
OK = operational channel
FAIL = error
• Polarity (the polarities are selected via the BENCFG Configuration Software of
the BEN 5000)
“+” = normal: the channel is in alarm when power is applied (N.O. contacts)
“-“ = inverted; the channel is in alarm when no power is applied (N.C. contacts)
3.2.2 Analog inputs window
This window allows you to choose the input ranges for each of the 8 channels (see
below). You can also view the working state of the different elements of the card.
• The channel locations for the 8 analog inputs that this board is monitoring.
• Input field for the shunt value of a current input. Select the field with the arrow
keys and enter the value (220V, 110V, 30V, 12V, 5V, 2V, OFF, 55V, 15V, 6V,
2.5V, 1V, 220/SH, 110/SH, 30/SH, 12/SH, 5/SH, 2/SH, 15/SH, 6/SH, 2.5/SH,
1/SH). The /SH extension indicates to the software to take into account the value
in the shunt field and use A or mA as the unit. Be sure to put the jumpers on the
analog isolation boards in the right position, as the program does not read the
position.
• Position of electronic potentiometer 0 →511
• The 'RMS' column indicates, for each channel, if the RMS filter is installed or not
(Yes/No).
• Hardware status (OK/Fail)
The columns 'MF6', 'RMS', 'OFFSET' and 'GAIN' indicate the normal running (OK)
or a malfunction (FAIL) for each of the 8 channels . The ‘MF6’ corresponds to the
Anti-aliasing filter.
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3.2.3 Input ranges
VOLTAGE CURRENT
Max. input value Max. input value
Range AC RMS DC Range AC RMS DC
2V 2V 2.8284V 2/SH 2/Shunt A 2.8284/shunt A
5V 5V 7.0710V 5/SH 5/Shunt A 7.0710/shunt A
12V 12V 16.9700V 12/SH 12/Shunt A 16.9700/shunt A
30V 30V 42.4260V 30/SH 30/Shunt A 42.4260/shunt A
110V 110V 155.5600V 110/SH 110/Shunt A 115.5600/shunt A
220V 220V 311.1200V 220/SH 220/Shunt A 311.1200/shunt A
Additionally, on a 424-03 board, you can select the divide by 2 jumper for any
channel, and halve the above listed maximum input values.
For current inputs, a shunt is added in parallel with the input. The current ranges are
equal to the voltage ranges in Volts divided by the shunt values in Ohms.
Unless special shunts are used, the maximum current for 1s is 100 A RMS for the
0.1Ωshunts and 30 A RMS for the 0.47Ωshunts.
For current loops in the range of 0-20 mA, range 1 will be used.
3.2.4 Setting input ranges
To change input voltage ranges (V RMS), move to the 'RANGE' column by using the
vertical arrow. Press the spacebar to toggle through the possible ranges. Check that
the input range selectors J1 ... J4 are correctly placed on the 5424 isolation cards.
For current inputs, choose a 'RANGE' with the '/SH' suffix, and enter the shunt value
in the 'SHUNTS' column.
Note 1 : For voltage inputs, the 'SHUNTS' values must always be left at zero.
For current inputs, the 'SHUNTS' values must never be equal to zero.
Note 2 : For shunt values higher than 10 ohms, you must introduce the resulting
value of the shunt in parallel with the input impedance of the isolation
card, which is 10 K ohms on range 1.
Example : if the shunt value is 143 ohms, you must introduce a value
of 143//10000 = 141 ohms.
Note 3 : During the initial calibration of a 623 card, all the ranges are initialized
to an 'OFF' value. This value has no physical meaning, but disables the
calibration functions. This forces the operator to select range values,
and to check the corresponding jumpers on the 424 isolation cards, in
order to calibrate the channels.
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Calibration Primary Training
When the range for each channel has been set up, quit the AUTOCONFIG window
by moving the arrows to the <OK> firld and press <ENTER>.
3.3 Calibrate menu
Place the cursor on the CALIBRATE menu, and select this choice with the
<ENTER> key.
3.3.1 Selection of the channels to be calibrated
A list representing the 8 channels appears on the screen:
SPACE to select AC/DC cal.
DC calibration
Channel 11A1 (Voltage )
Channel 11A2 (Voltage )
Channel 11A3 (Voltage )
Channel 11A4 (Voltage )
Channel 11A5 (Voltage )
Channel 11A6 (Voltage )
Channel 11A7 (Voltage )
Channel 11A8 (Voltage )
Calibration
Mode field
Select the calibration mode (DC mode, AC 50 Hz mode or AC 60 Hz mode) by
pressing the <SPACE> key while the calibration mode field is selected.
NOTE:When AC mode is selected, a sine-wave signal with a frequency of 50 Hz ±0.1 Hz
or 60 Hz ±0.1 Hz must be used.
The calibration can be carried out on one or up to four channels at a time, as long as
they are on the same range and have the same shunt value. Select the channels to be
calibrated with the vertical arrows and mark it with the space bar.
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3.3.2 Offset calibration
Start the calibration process by pressing <ENTER>. First, the software will correct
the offset : you will be prompted to short the corresponding analog inputs.
Offset correction
Please, short cut the analog
input number : 1
Press OK to calibrate offset
OK CANCEL
When the input has been shorted, move the cursor to the <OK> icon and select with
<ENTER>.
The software begins the offset adjustment. If this operation is successful, the software
will adjust the gain. If the offset is not adjusted correctly, an error message appears.
This error is often due to a poor shorting of the input, or the range jumpers not being
installed in the location you selected in the AUTOCONFIG menu.
It is important to note that the <CANCEL> icon allows you to return to the previous
level in the software.
3.3.3 Gain calibration
3.3.3.1 DC mode gain calibration
This mode must be carried out using DC voltages or currents.
The gain adjustment can be made as soon as the offset adjustment has been
completed. The program suggests a voltage or current value to be applied to the
channel inputs to be calibrated (approximately 80% of the range). If this voltage is
not available, the user can enter another one instead of the one suggested.
This voltage must be between 0.1 and the chosen range multiplied by √2. Type
<ENTER> to accept this value.
In the following example, the range chosen is 2V RMS on channel 1. The program
suggests 2 Volts DC. If this voltage is not available, the user can enter any value
between 0.1 and 2.828 Volts DC (the higher the voltage is, the more precise the
calibration will be). Take care when calibrating current inputs for the dissipated heat
and do not exceed the maximum allowed values.
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Calibration Primary Training
DC Gain correction
Input the value of the DC voltage
connected to the analog input (s)
number : 1
(Range is : 2.828 Volts)
Value = 2 Volts
OK to calibrate input
Offset correction
Apply to the input the same voltage as entered on the screen, then move the cursor to
the [OK] icon, and press [ENTER]. The software starts the gain adjustment. As for
the offset, if this adjustment is unsuccessful it will be indicated by an error message
appearing on the screen.
The error of gain adjustment can be due to the application of a voltage that does not
correspond to the voltage entered on the screen, or to a wrong input range selection, a
mis-placed jumper on the 424 isolation cards, or an unstable DC calibration source
(ripple).
3.3.3.2 AC mode gain calibration
This mode must be carried out using AC voltages or currents.
For optimum precision, a sine-wave generator with a frequency of 50HZ ±0.1 Hz or
60 Hz ±0.1 Hz must be used. The program calculates the true RMS value, so check
the input value with a true RMS voltmeter of adequate precision. The program
suggests an AC voltage value to be applied to the channel inputs to be calibrated
(approximately 80% of the range). If this voltage is not available, the user can enter
another one instead the one suggested. This voltage must be between 0.1 and the
chosen range. Type <ENTER> to accept this value.
In the following example, the range chosen is 2V RMS on channel 1. The program
suggests 1V RMS. If this voltage is not available, the user can enter any value
between 0.1 and 2V RMS AC (the higher the voltage is, the more precise will be the
calibration. Be carefull when calibrating current inputs for the dissipated heat and do
not exceed the maximum allowed values).
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AC Gain correction
Input the value of the AC voltage
connected to the analog input (s)
number : 1
(Range is : 2 Volts RMS)
Value = 1 Volts RMS
OK to calibrate input
Offset correction
Apply to the input the same voltage as entered on the screen, then move the cursor to
the [OK] icon, and press [ENTER]. The software starts the gain adjustment. As for
the offset, this adjustment can be unsuccessful, and will be indicated by an error
message appearing on the screen.
The error of gain adjustment can be due to the application of a voltage that does not
correspond to the voltage introduced on the screen, or to a wrong input range
adjustment, a mis-placed jumper on the 424 isolation cards, or an unstable AC
calibration source.
3.3.4 Notes
When an input range is changed on the isolation card, the calibration process must be
completed again.
For better precision, the reference source (voltage or current) used during calibration,
must be between 50% and 100% of the selected range, except for high current ranges,
see further.
The low value resistor shunts (for example 0.1Ω, 0.47Ω,...) are not able to withstand
the maximum current continuously (see shunt specifications, SENS 224-xx).
Therefore, it is highly recommended to calibrate such inputs with the nominal current
values, i.e. 5 to 10 amps RMS for 0.1Ωshunts, and 1 to 5 amps RMS for 0.47Ω
shunts. This way, the power dissipation will be the same during calibration as during
normal use, canceling gain drift due to temperature variation of the shunt.
When DC calibration mode is used, the polarity of the reference signal must be
respected. Only positive signals are used. Terminals numbered 1, 2, 3, 4, 5,6 7 and 8
are the positive input wires; terminals numbered 10, 11, 12, 13, 14, 15, 16, 17 and 18
are the negative input wires.
When AC calibration mode is used, the reference signal must be a sine-wave, with a
frequency of 50Hz +/- 0.1Hz when 50Hz mode is selected, and 60Hz +/- 0.1Hz when
60Hz mode is selected.
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On current inputs, terminals type RTK/S are provided with short-circuit bridges to
short out the field inputs. The operator must therefore move the bridge to short out
the field inputs, and screw it very tightly, before having access to the sliding switches
of the terminals; the switches may then be opened to disconnect the input circuit from
field wiring.
After calibration, remove the reference current source, close the sliding switches of
the terminal, tighten them firmly, then unlock the short-circuit bridge.
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3.3.5 End of calibration
Following the previously explained procedure, you can calibrate each channel of the
623 card. To calibrate the other 623 cards present in the BEN, first exit the program
using the [EXIT] command, wait until the acquisition error on the LCD screen of the
BEN disappears, then remove the RS-232 connector of the card and connect it to the
next card. Do not use the <escape> key to exit the program!
Warning : NEVER remove the RS-232 cable before exiting the
program, otherwise calibration data will be lost.
After you disconnect the link between the PC and 623, the card goes on functioning
normally, and transmits the acquisition data to the processing unit.
If a channel is in the OFF position and you ask for a calibration process, the
following message appears on the screen:
The channel 5 is not enabled
RUN AutoConfig
OK
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3.4 Measure menu
Place the cursor on the MEASURE menu and accept with the <ENTER> key. This
menu allows you to display in real time the different values measured at each of the 8
analog channels and the 24 digital channels.
This function can be used to check the status of the acquisition system. The correct
reading indicates proper operation of the chain : 'terminal block' - 'isolation' -
'acquisition'.
All channels measurement
Digital inputs
11B1 : + OFF
Ch. Pol Value
11B2 : + OFF
11B3 : + OFF
11B4 : + OFF
11B5 : + OFF
11B6 : + OFF
11B7 : + OFF
11B8 : + OFF
11C1 + OFF
11C2 : + OFF
11C3 : + OFF
11C4 : + OFF
Ch. Pol Value
11C5 : + OFF
11C6 : + OFF
11C7 : + OFF
11C8 : + OFF
11D1 : + OFF
11D2 : + OFF
11D3 : + OFF
11D4 : + OFF
11D5 : + OFF
11D6 : + OFF
11D7 : + OFF
11D8 : + OFF
Analog inputs
Ch. Range Value
11A1 : 2 - 1.10626 Volts
11A2 : 2 - 2.82849 Volts
11A3 : 2 - 0.96539 Volts
11A4 : 2 - 2.82849 Volts
11A5 : 2 - 2.82849 Volts
11A6 : 2 - 1.26508 Volts
11A7 : 2 - 0.38533 Volts
11A8 : 2 - 0.08010 Volts
Close DC measure
The icon "DC measure" may be toggled to "AC measure" with the <SPACE> bar.
To quit this screen, press <ESCAPE> key or go to the [CLOSE] icon.
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4 APPENDIX 1 : HOW TO HANDLE INPUT
TERMINALS FOR CALIBRATION
4.1 Calibration of one voltage input
Voltage input with interruptible terminals
(RTK/S, MTK P/P,...)
Voltage input without interruptible
terminals
(SSK110, UK4,...)
Offset calibration
1. Open switches of both terminals (n,
n+10)
2. Short cut voltage inputs, BEN side
3. Start offset calibration process, wait
end of process
4. Remove short-circuit
Offset calibration
1. Disconnect USER wires from both
terminals
2. Short cut voltage inputs
3. Start offset calibration process, wait
end of process
4. Remove short-circuit
Gain calibration
5. Apply reference voltage source, BEN
side
6. Start gain calibration process, wait end
of process
7. Remove reference voltage source
8. Close switches of both terminals
Gain calibration
5. Apply reference voltage source
6. Start gain calibration process, wait end
of process
7. Remove reference voltage source
8. Connect USER wires again to both
terminals
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4.1.1 Calibrate one voltage input with interruptible terminals (RTK/S, MTK
P/P,...)
1. Open switches of both terminals
TERMINALS
+
-
+
-
USER
SIGNAL
11A1
+
-
INPUT
CARD
11A11
USER SIDE BEN SIDE
REFERENCE
VOLTAGE
SOURCE
2. Short cut voltage inputs, BEN side
TERMINALS
+
-
+
-
USER
SIGNAL
11A1
+
-
INPUT
CARD
11A11
USER SIDE BEN SIDE
REFERENCE
VOLTAGE
SOURCE
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