RDP CUSTOMER DOCUMENT
Technical Manual for the
E725 Microprocessor based
Transducer Indicator/Controller
DC Input Version
Doc. Ref CD1421J
Issue J
This manual applies to units of mod status 6 ONWARDS
BS EN ISO 9001 / 1987
Certificate No. FM13141
USA & Canada
RDP Electrosense Inc.
2216 Pottstown Pike
Pottstown, PA 19465
U.S.A.
Tel (610) 469-0850
Fax (610) 469-0852
E-mail sales@rdpelectrosense.com
www.rdpelectrosense.com
Affirmed by Declaration
of Conformity
All other countries
RDP Electronics Ltd
Grove Street, Heath Town,
Wolverhampton, WV10 0PY
United Kingdom
Tel: +44 (0)1902 457512
Fax: +44 (0)1902 452000
E-mail: sales@rdpelectronics.com
www.rdpelectronics.com
Blank Page
2
INDEX
1
INTRODUCTION ..........................................................................................................5
1.1
1.2
1.3
2
EMC DECLARATION & SAFETY TEST INFORMATION.............................................7
2.1
2.2
2.3
3
Transducer Connection Overview & Specification...............................................14
Connections for Unamplified Strain Gauge Transducer ......................................15
Connections for Amplified Voltage Output Transducers ......................................16
Connections for Potentiometric Transducers.......................................................16
Connections for 3 wire 4 to 20mA Transmitters...................................................16
Connections for 2 wire 4 to 20mA Transmitters...................................................16
PROGRAMMING........................................................................................................17
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
7
Display Features..................................................................................................11
Control Key Functions .........................................................................................11
External Digital Input Controls .............................................................................12
TRANSDUCER CONNECTION DETAILS..................................................................14
5.1
5.2
5.3
5.4
5.5
5.6
6
Power Supply Voltage Selection and Connection..................................................9
Display During Power-Up ......................................................................................9
Changing the Fuse ..............................................................................................10
Panel Mounting....................................................................................................10
FRONT PANEL DETAIL & EXTERNAL DIGITAL INPUT CONTROLS ......................11
4.1
4.2
4.3
5
Electrical Safety Checks........................................................................................7
EMC Compliance...................................................................................................7
Certificate of EMC Conformity. ..............................................................................8
INSTALLATION ............................................................................................................9
3.1
3.2
3.3
3.4
4
E725 DC Input Version..........................................................................................5
How to Use This Manual .......................................................................................5
Part Number Structure...........................................................................................6
Programming Overview .......................................................................................17
Menu Access .......................................................................................................17
Number Entry ......................................................................................................18
Menu Item Selection............................................................................................19
Front Panel ..........................................................................................................20
Edit Passwords....................................................................................................20
Filter ....................................................................................................................21
Count Facility.......................................................................................................21
Returning To Normal Operating Mode.................................................................22
Menu Map See Section 6.2 for menu access .....................................................22
CALIBRATION............................................................................................................23
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
Calibration Overview ...........................................................................................23
Excitation Voltage................................................................................................24
Gain Range .........................................................................................................25
Decimal Point ......................................................................................................26
Calibrate Input .....................................................................................................27
Shunt Calibration as A Calibration Check............................................................33
Linearise Input .....................................................................................................33
Engineering Offset...............................................................................................33
Tare Point ............................................................................................................34
3
8
ANALOGUE OUTPUT ................................................................................................35
8.1
8.2
8.3
9
Analogue Output Description...............................................................................35
Analogue Output Connections & Specification ....................................................35
Analogue Output Calibration ...............................................................................35
LIMITS ........................................................................................................................37
9.1
9.2
9.3
10
10.1
10.2
10.3
10.4
10.5
11
11.1
11.2
11.3
Limits Description ................................................................................................37
Connections and Specification ............................................................................37
Programming Limits.............................................................................................39
MAX /MIN (PEAK CATCHER) ................................................................................41
How to Identify if Your E725 Has an Option FM Card Fitted ...............................41
MAX/MIN Description (E725 Without Option FM)................................................41
MAX/MIN Description (E725 With Option FM).....................................................41
MAX/MIN Connections and Specification (E725 Without Option FM)..................42
MAX/MIN Connections and Specification (E725 With Option FM).......................42
TWO CHANNEL VERSIONS ..................................................................................43
Description ..........................................................................................................43
Connections for Second DC Input Channel.........................................................44
Calibrating the Second Transducer .....................................................................44
12
RS232/RS485 OUTPUTS .......................................................................................44
13
SPECIFICATION.....................................................................................................45
14
GLOSSARY OF TERMS.........................................................................................46
15
COMMON CONVERSION FACTORS ....................................................................48
16
APPENDIX 1 DIMENSIONAL DETAILS .................................................................49
17
APPENDIX 2 – COMPLETE CONNECTION LISTING ...........................................50
18 WARRANTY AND SERVICE .......................................................................................51
4
1
INTRODUCTION
YOU DO NOT NEED TO READ THE ENTIRE MANUAL.
Read this section to find out which sections are important.
1.1
E725 DC Input Version
There are several types of unit in the E725 range. This manual is specifically for use with
E725 units fitted with dc input board(s). Before proceeding, please check that the part
number (located on a label on the E725 housing) has the following structure.
E725-XXX-DCX-X-X-X where X is unimportant for the purposes of this exercise.
The DC input version of the E725 is designed to work with a wide range of strain gauge,
potentiometric and internally amplified transducers. It provides a display for DC type
transducers. It has an analogue output (voltage and current) and four limits as standard. It
has excellent dynamic performance and several sophisticated features. One of several
option boards can be factory fitted.
1.2
How to Use This Manual
This manual contains all of the information needed to connect and calibrate your
transducer. Please spend a little time to read and understand the relevant sections. It is
not necessary to read all sections. Please use the index to select the sections relevant to
your application.
It is possible that the unit is already calibrated with a transducer. If you have purchased the
unit with a calibration then you can probably ignore all sections concerning programming
and calibration.
If your unit is not calibrated then read Sections 3, 4, 5, 6 and 7 as a minimum.
5
1.3
Part Number Structure
SUPPLY
INPUT BOARD
(One must be
chosen)
OPTION BOARD
(None or one may
be chosen)
SERIAL OUTPUT
230
115
105
5
12
24
AC
DC1
DC2
DC3
0
R
RS
FR
FRS
FM
2AC
2DC1
2DC2
2DC3
0
1
0
SPECIAL OPTION
Example:E725 - 230 - AC - FR - 0 - 0….
= 230V ac +5/-15%
= 115 " "
= 105 " "
= 5V dc +50/-25%
= 12 " "
= 24 " "
= for LVDT/half-bridge etc.
= for strain gauge and amplified transducers (±15V supply provided)
= for amplified transducers (24V supply voltage provided)
= for RDP D2 series transducers
= none
= four mechanical limit relays
= four solid state limit relays
= fast limits with two mechanical relays
= fast limits with two solid state relays
= fast MAX/MIN board
= Second LVDT/Half-bridge input
= Second DC1 input
= Second DC2 input
= Second DC3 input
= RS232
= RS485
= None
…has 230V ac supply, and AC input board, a fast limit card, RS232
output and no special options
6
2
EMC DECLARATION & SAFETY TEST INFORMATION
2.1
Electrical Safety Checks
This unit is designed to comply with EN 61010-1 "Safety requirements for electrical
equipment for measurement, control and laboratory use". The specification complies with
the EEC Directive 72/73/EEC concerning low voltage electrical safety.
This unit was checked for electrical safety, using a portable appliance test unit, prior to
despatch.
If the user wishes to carry out his own PAT tests, the following points must be followed.
1)
This Safety Class 1 apparatus has a low fuse rating (<3A), and a low current rated
power connection cable.
2)
It is recommended that when carrying out an earth bond test (BS4743, Section
9.5.5.), the test current of 25A should not be applied for more than six seconds.
3)
In general it is not recommended that high voltage (e.g. 1.5kV) insulation tests are
carried out (BS4743, Section 9.7.4). This could cause damage to suppressor
components.
2.2
EMC Compliance
This unit is designed to comply with EN61326-1 "EMC requirements for electrical
measurement equipment".
For full EMC compliance, only shielded multi-core cables should be used for connection to
this unit; the cable shield to be terminated by means of a short "pig-tail" and connected as
detailed in relevant sections of this manual.
The metal rear panel is used as a ground connection for all cable shields. The panel is
internally connected to the supply earth wire that must be connected to a reliable ground.
Notes:
1)
Cable shields to be earthed at only one end - the E725 end.
2)
Ensure cables to and from the unit are routed away from any obviously powerful
sources of electrical noise, e.g. electric motors, relays, solenoids and electrically
noisy cables.
3)
Ideally, the transducer body should not be connected to the cable shield, but should
be separately earthed. If the transducer fixing attachments do not provide a good
earth, then an earth strap should be used.
7
2.3
Certificate of EMC Conformity.
DECLARATION OF CONFORMITY
RDP ELECTRONICS LTD.
Grove Street Heath Town
Wolverhampton West Midlands
WV10 0PY
United Kingdom
We declare that the product described in this technical manual is manufactured by
RDP Electronics Limited and performs in conformity to the following:
The Electromagnetic Compatibility Directive 89/336/EEC
The Low Voltage Safety Directive 72/23/EEC
P. J. Smith, C.Eng., MIEE
Director
RDP Electronics Limited
8
3
INSTALLATION
3.1
Power Supply Voltage Selection and Connection
Check the supply requirement for the unit using the part number located on the outside of
the unit housing:
E725-XXX (ignore the rest)
If XXX = 5
then supply required is 5V dc, 7W
+50/-10%
If XXX = 12
then supply required is 12V dc, 7W
+50/-25% dc Supply
If XXX = 24
then supply required is 24V dc, 7W
+50/-25%
If XXX = *105 then supply required is 105V ac, 7VA +5/-15%
ac Supply
If XXX = *115 then supply required is 115V ac, 7VA +5/-15%
(50-60Hz)
If XXX = *230 then supply required is 230V ac, 7VA +5/-15%
*In these cases check that the supply selection slider-switch is correctly set.
The E725 is fused internally but it is recommended that the unit be externally fused also.
We suggest a fuse of a slightly lower rating to the internal fuse (details in Section 3.3)
As this unit has no power switch, it is recommended that an external means of
disconnection is fitted in a convenient location.
The ac power supply is connected to the three-core 2m long integral cable as follows:Cable Core
Supply
Brown
Live
Blue
Neutral
Green/yellow
Ground (Earth)
The optional dc supply, has integral 2m, two-core shielded cable as follows:Cable Core
Supply
Red
dc volts positive
Blue
dc volts negative
Shield (connect to good ground for optimum EMC) 0v/ground
3.2
Display During Power-Up
On power-up the display shows the following before assuming normal operating mode:Step
1
2
3
4
Display
E725
X.XX
AC-X
XX.Y.Z
Brief description.
The product model number
A number indicating the software version
AC input. X =option card 1 to 4
The serial communication settings
9
Example
E725
1.00
AC-1
00.0.4
3.3
Changing the Fuse
As the fuse is inside, it is necessary to open the unit in order to change the fuse. Firstly,
please obtain the correct fuse as shown below. Section 3.1 details how to identify the
power supply required by your unit.
230V ac, 115V ac &
105V ac
5V dc
12V dc
24V dc
units require a
250mA
unit requires a
unit requires a
unit requires a
3.15A
1A
0.5A
anti surge (A-S/T type) 20mm long,
5mm diameter
anti surge, 20mm long, 5mm dia.
anti surge, 20mm long, 5mm dia.
anti surge, 20mm long, 5mm dia.
DO NOT USE ANY OTHER VALUE OR TYPE OF FUSE. IT WILL INVALIDATE THE
GUARANTEE, IT IS DANGEROUS AND IT MAY CAUSE A FIRE.
How to install the fuse.
1)
2)
3)
4)
6)
7)
DISCONNECT THE POWER AND ALL CONNECTORS FROM THE UNIT.
Place the unit on an anti-static mat and wear earth strap on wrist.
Remove the four screws, one at each corner of the rear panel.
Hold the power supply cable grommet and pull the rear panel and circuit boards
gently from the unit.
Remove the two screws that hold the power supply board. The power supply board
is on the top of the unit, at the front (near the display).
Lift the power supply board to reveal the fuse.
Replace the fuse and re-assemble the unit.
3.4
Panel Mounting
5)
This unit may safely be used on a bench or as a portable unit providing that it is not
mechanically damaged (by dropping etc) and providing that the supply cable is not
damaged.
It may also be installed into a panel if desired.
Panel mounting procedure
The maximum acceptable panel thickness is 12mm. A hole must be cut in the panel 93mm
wide and 45mm high. Pass the unit through the panel by firstly feeding the cables through
the hole from the outside (front) of the panel and then inserting the unit rear end first.
From the inside of the panel fit the panel-mount clips into the slots on the side of the
housing and tighten until the unit is firmly fixed into the panel.
Sealing the front of the unit in a panel.
The membrane keypad of the E725 is sealed into its housing. In order to achieve a seal
into the panel, silicone sealant should be applied liberally between the front of the panel
and the rear of the unit bezel. This is best done prior to tightening the unit into its panel.
The degree of protection is dependent upon how well this job is done but IP65 is possible.
10
4
FRONT PANEL DETAIL & EXTERNAL DIGITAL INPUT CONTROLS
4.1
Display Features
The up arrow indicates that the display is showing the MAX value, the down arrow
indicates that MIN is being displayed and both together indicate that the TIR is being
displayed. (Section 10 refers). The horizontal bar between the up and down arrows
provides the negative indication when all 5 digits are in use.
Four control keys provide
The E725 has 5
functions as described in
digits each 13.2mm
section 4.2.
in height.
Four LEDs (F1 to F4) The white area below the centre of the
show the display function digits provides space for one of the
MODE. These LEDs are legend labels (supplied) to be fixed.
not used on units with a
single
input
unless
calculated channels are
assigned (Sections 11
and 12 refer).
4.2
Four LEDs indicate
the status of the
LIMITS.
An
illuminated
LED
indicates that a
particular LIMIT has
been
triggered
(Section 9 refers).
Control Key Functions
The E725 has four membrane keypads with tactile feedback. These keys select and
control the functions of the E725. This section concerns itself only with the functions
available in the E725's normal operating mode, it does not detail any of the programming
or calibration functions.
Key functions. In order to...
Press…
Zero the display
ZERO
Return to calibration zero (clear Zero)
ZERO
Change display (MAX to MIN to TIR to
NORMAL)
MODE
Reset (MAX & MIN & TIR)
MODE
Change function mode (if available)
MODE
Display shunt cal reading (see section 7.6)
MODE
Reset latched limits
LIMITS
11
ZERO
ZERO
& RESET
SETUP
RESET
together
MODE
MODE
MODE
MODE
LIMITS
ENTER
& RESET
& FUNC.
& CAL
SETUP
RESET
ZERO
LIMITS
ENTER
& RESET
together
together
together
SETUP
RESET
together
4.3
External Digital Input Controls
Two versions apply; one with opto-isolated inputs (labelled with a MOD number,
e.g. MOD6, etc.), and one without isolated inputs, i.e. direct TTL inputs (labelled
with a MOD number and a suffix A, e.g. MOD6A or 7A etc.).
Connections are made via the 15-way connector as shown in 4.3.1 and 4.3.2.
4.3.1 Opto-Isolated Inputs
Digital Input functions. In order to...
Zero the display
Return to calibration zero (clear Zero)
Change display (MAX to MIN to TIR to NORMAL)
Reset (MAX & MIN & TIR)
Change Function mode (if available)
Shunt Calibration
Reset latched limits
Freeze Display (Digital HOLD)
Perform a fast analogue hold.
Apply 5-50V between pins…
(14 and 10)
(14 and 10) AND (14 and 12)
(14 and 9)
(14 and 9) AND (14 and 12)
(14 and 9) AND (14 and 10)
(14 and 9) AND (14 and 11)
(14 and 11) AND (14 and 12)
(14 and 12)
(14 and 13)
Connections are made via the 15 pin D type connector (labelled 'DIGITAL I/O') on the rear
panel. In order to activate the functions a voltage of between 5 and 50V dc is applied
between input com. (pin 14) and the required function pin. As the inputs are opto-isolated it
is best to use an external supply as this gives the best protection for the unit against
electrical interference. If this is not possible, a 5V output available from the same
connector may be used, but opto isolation will be lost. If the 5V output from the E725 is
used, the common (pin 14) must be grounded by connecting it to pin 8.
15 Pin DIGITAL I/O connector. Pins available for digital inputs.
Pin
Description
8.
Ground
9.
Same as MODE key for these purposes
10.
Same as ZERO key for these purposes
11.
Same as LIMITS key for these purposes
12.
Same as RESET key for these purposes and also digital HOLD.
13.
Fast analogue HOLD.
14.
Common for all digital inputs
15.
+5V supply for digital i/p. If used, common (pin 14) must be linked to ground (pin 8).
Example of resetting MAX/MIN
Using an external power supply
Using the 5V supply output
12
4.3.2 TTL Inputs
Digital Input functions. In order to...
Zero the display
Return to calibration zero (clear Zero)
Change display (MAX to MIN to TIR to NORMAL)
Reset (MAX & MIN & TIR)
Change Function mode (if available)
Test amp circuits. Should display 1.100 APPROX.
Reset latched limits
Freeze Display (Digital HOLD)
Perform a fast analogue hold.
Apply TTL Low to Pin…
10
10 and 12
9
9 and 2
9 and 10
9 and 11
11 and 12
12
13
15 Pin DIGITAL I/O connector. Pins available for digital inputs.
Pin
Description
8 & 14
Ground (Common/0V)
9.
Same as MODE key for these purposes
10.
Same as ZERO key for these purposes
11.
Same as LIMITS key for these purposes
12.
Same as RESET key for these purposes and also digital HOLD.
13.
Fast analogue HOLD.
4.3.3 Digital Inputs – Specification (Both Versions)
Function
All digital inputs except hold
Digital hold, remove signal to release
Analogue fast hold, remove signal to release
Min. pulse
200ms
200ms
0.1ms
Response
200ms max
200ms max
0.1ms
Droop
N/A
None
1 digit/sec typ.
The fast analogue hold freezes both the display and the analogue output. Because it is
held as an analogue voltage, it is prone to droop. For best results, Applying the hold to the
digital hold 200ms after the analogue hold (a simultaneous hold may be acceptable) will
eliminate display droop. However, the analogue output will still droop.
13
5
TRANSDUCER CONNECTION DETAILS
5.1
Transducer Connection Overview & Specification
The E725 provides input voltage (usually called excitation or supply voltage) for most
types of DC transducer, as well as amplifying and displaying the output of the transducer.
Please check the specific input card type (DC1, DC2 or DC3) from the part number label
on the top of the E725 housing. Select which connection arrangement is appropriate from
the following table.
Please note that there are voltages present in the connector which have the potential to
destroy certain types of transducer, therefore please follow the instructions carefully.
Check your wiring before connecting the transducer to the E725.
Transducer type or requirements
Input card type
Unamplified strain gauge bridge transducer.
3 to 10V and ±15V supplies and Voltage
output.
23V supply and Voltage output
15V supply and Voltage output
Potentiometric. (Pot)
30V supply and 4-20mA output (3 wire type)
23V supply and 4-20mA output (2 wire type)
Any DC version
DC1
Connection
arrangement
Secton 5.2
Connections Table
DC2
DC1
Any DC version
DC1
DC2
Connections Table
Section 5.3
Section 5.4
Section 5.5
Section 5.6
CONNECTIONS TABLE for 9 pin D type connector labelled 'TRANSDUCER'
PIN
1
2
3
4
5
6
7
8*
9
Shell
Input card type DC1
Input card type DC2
Input card type DC3
1.5, 3, 5 and 10V (±5%) (Bipolar and selectable), 100mA max. E.g. for 3V
selection, pin 1 has +1.5V and pin 2 has -1.5V. Section 7.2 has info. on setting
the voltage.
Signal +
Signal +
Signal +
Signal Signal Signal 0v (Ground)
0v (Ground)
0v (Ground)
Shunt calibration (with 9)
N/C
N/C
+15V output, 100mA
+15V output,100mA
+15V output, 100mA
-15V output*, 100mA
-8V output*, 100mA
-6V output*, 100mA
Shunt calibration (with 6)
N/C
N/C
Cable shield
Cable shield
Cable shield
For example, to obtain a nominal 24V supply (actually 23V) from DC2, take the supply
between pins 7 and 8 where there is a 23V potential difference.
*Due to the fact that this can be changed, it is recommended that the voltage between pins
8 and 5 be measured and checked prior to connecting the transducer.
14
5.2
Connections for Unamplified Strain Gauge Transducer
Section 7.2 contains additional information on excitation.
Section 7.5 (EXAMPLE M) and section 7.6 contain additional information on shunt
calibration.
Without shunt calibration
1
2
3
4
5,6,7,8 & 9
Shield
Excitation +
Exciation Signal +
Signal No connection
Connect to shell of connector
Any DC input
card
With shunt calibration- simple approach.
This approach is suitable for short cables typically <5m. For longer cables and for optimum
accuracy use 'best approach' shown below.
1
2
3
4
5
6
7&8
9
Shield
Excitation +
Exciation Signal +
Signal No connection
Shunt cal
No connection
Shunt cal
Connect to shell of connector
Any DC input
card
Excitation +
Exciation Signal +
Signal No connection
Shunt cal
No connection
Shunt cal
Connect to shell of connector
Any DC input
card
With shunt calibration- best approach
1
2
3
4
5
6
7&8
9
Shield
15
5.3
Connections for Amplified Voltage Output Transducers
INPUT CARD TYPE DC1
The example shows a sensor that requires a
15V supply and has a voltage output. As the
input to the E725 is floating, the common of
the transducer need not be 0V.
Other supply arrangements may be required.
Refer to CONNECTIONS TABLE for
alternatives.
5.4
7 = +15V
5 = 0V
3 = Signal +
4 = Signal -
Connections for Potentiometric Transducers
ANY DC INPUT CARD
*The example shows a potentiometric
transducer operating from a ±5V supply. In
order to set the supply, the excitation must be
changed as detailed in section 7.2.
5.5
1 = +5V*
2 = -5V*
3 = Signal +
4 = Signal 5 = 0V
Connections for 3 wire 4 to 20mA Transmitters
INPUT CARD TYPE DC1
7 = +15V
8 = -15V
4 = Signal 3 = Signal +
The example shows a 3 wire 4-20mA
transmitter with a 30V supply. Fit the
resistors inside the connector.
5.6
Connections for 2 wire 4 to 20mA Transmitters
INPUT CARD TYPE DC2
The example shows a 2 wire 4-20mA
transmitter with a 23V supply. Fit the resistor
inside the connector.
16
7 = +15V
3 = Signal +
4 = Signal 8 = -8V
6
PROGRAMMING
6.1
Programming Overview
Various features of the E725 are user-programmable. This section of the manual outlines
the general approach to programming and describes some specific programming steps.
Reading Section 6 should enable the user to access menus, enter numbers, select items
and programme some specific features. Programming detail relating to calibration, limits
and two channel operation are covered in Sections 7, 9 and 11 respectively.
SEVERAL EXAMPLES ARE GIVEN, THEY ARE HIGHLIGHTED IN BOXES AND BY THE USE OF
THOSE IN BOLD PRINT ARE LIKELY TO BE PARTICULARLY USEFUL TO THE FIRST TIME USER.
THIS FONT.
It is possible that the E725 has been supplied factory calibrated for use with a
specific transducer. In this case, programming may be unnecessary. Care should be
taken if programming is attempted as errors may cause the loss of calibration data.
6.2
Menu Access
The E725s programming procedure is based on a menu approach. There are three menus
which are called the CONFIGURATION, CALIBRATION and USER SETUP menus.
Access to the menus is protected by three passwords. Each password is in fact a five digit
number (i.e. five digits including leading zeros and sign). The passwords are called P1, P2
and P3.
The factory default values and access provided by each password are as follows:Password
P1
P2
P3
Default
00001
00002
00003
Access
USER SETUP menu
CALIBRATION and USER SETUP menus
CONFIGURATION, CALIBRATION and USER SETUP menus
It should be noted that the procedure for accessing the CONFIGURATION, CALIBRATION
and USER SETUP menus is almost identical. The only difference is the user level which
has to be selected and password which has to be entered.
Each menu offers several items, which allow particular features to be programmed. Once
a menu has been accessed, the user can step forwards and backwards through that
menu, making particular items appear on the display. Once an item is displayed it can be
selected to allow a feature to be programmed.
The structure of CONFIGURATION, CALIBRATION and USER SETUP menus is shown in
Section 6.9. The CONFIGURATION menu automatically leads in to the CALIBRATION
menu which, in turn, automatically leads in to the USER SETUP menu. In this way the
CONFIGURATION menu gives full access to all user-programmable features.
17
EXAMPLE A
TO ACCESS A MENU FROM THE UNIT'S NORMAL OPERATING MODE, PRESS THE SETUP KEY FOR
AT LEAST ONE SECOND. THE DISPLAY WILL SHOW THE PROMPT [UL 1]. PRESS THE MODE KEY
TO STEP THROUGH THE VARIOUS OPTIONS, WHICH ARE:DISPLAY
ACCESS
USER SETUP MENU
[UL 1]
CALIBRATION AND USER SETUP MENU
[UL 2]
CONFIGURATION, CALIBRATION AND USER SETUP MENU
[UL 3]
WHEN
THE REQUIRED USER LEVEL IS DISPLAYED, PRESS THE LIMITS KEY TO SELECT THE
DISPLAYED OPTION. THE DISPLAY WILL NOW SHOW A NUMBER ENTRY PROMPT [00000] WITH THE
LAST DIGIT FLASHING. AT THIS POINT THE RELEVANT PASSWORD SHOULD BE ENTERED (SEE
SECTION 6.3 FOR NUMBER ENTRY.)
6.3
Number Entry
Certain programming steps require number entry. When number entry is required, the
display shows a five-digit number with the last digit flashing.
The password number entry prompt is [00000]
In other cases (for example ENGINEERING OFFSET) any existing value is shown. For
example, if the existing value of ENGINEERING OFFSET is 1000, when ENGINEERING
OFFSET is selected, the display shows [0 1000], and the last digit is flashing.
Pressing the UP-ARROW and DOWN-ARROW keys increases and decreases the flashing
digit in the range 0 to 9.
Pressing the ENTER key accepts the current digit and causes the next (to the left) digit to
flash. The user must enter the required number working from right-to-left across the
display. The number contains five digits including leading zeros.
Pressing the RESET key at any stage in the number entry process discards changes and
restarts the process. The original existing value is displayed with the last digit flashing.
This is the only way of moving the flashing digit to the right.
A minus sign is entered with the most significant digit (i.e. the one to the left of the display).
When the most significant digit is flashing, pressing the UP-ARROW and DOWN-ARROW
keys increases and decreases the flashing digit in the range -9 to +9.
When the display shows the required new value, this number is entered in one of two
ways.
1) If the most significant digit is flashing, pressing the ENTER key enters the new value.
2) If any other digit is flashing, pressing the ENTER and RESET keys together enters thE
new value. (This alternative simplifies the entry of low values such as 00003, the default
value for password P3.)
In both cases the unit accepts the new value and goes to the relevant menu. The
display now shows the next item in the relevant menu. In the case of password number
entry, if an incorrect password is entered, the unit returns to its normal operating mode.
18
EXAMPLE B (THIS IS INTENDED TO ILLUSTRATE GENERAL POINTS).
TO ENTER THE PASSWORD -00031 FROM THE PASSWORD NUMBER ENTRY PROMPT.
DISPLAY SHOWS
00000
00001
00001
00031
00031
00031
00031
-00031
ACTION
1
PRESS UP-ARROW TO CHANGE DIGIT
2
PRESS ENTER TO STEP TO NEXT DIGIT
3
PRESS UP-ARROW THREE TIMES
4
PRESS ENTER TO STEP TO NEXT DIGIT
5
PRESS ENTER TO STEP TO NEXT DIGIT
6
PRESS ENTER TO STEP TO NEXT DIGIT
7
PRESS DOWN-ARROW FOR MINUS SIGN
8
PRESS ENTER TO ENTER PASSWORD
(AN UNDERLINED DIGIT REPRESENTS A FLASHING DIGIT)
EXAMPLE C
TO ENTER THE PASSWORD 00003 (FACTORY DEFAULT VALUE FOR PASSWORD P3) FROM THE
NORMAL OPERATING MODE.
DISPLAY SHOWS
ACTION
PRESS SETUP FOR AT LEAST ONE SECOND
1 Numeric Data
PRESS UP-ARROW TWICE
2
[UL 1]
PRESS ENTER TO SELECT THE USER LEVEL 3
3
[UL 3]
PRESS UP-ARROW THREE TIMES
4
00000
PRESS ENTER & RESET TOGETHER TO ENTER PASSWORD
5
00003
GAIN ACCESS TO CONFIGURATION MENU
(AN UNDERLINED DIGIT REPRESENTS A FLASHING DIGIT)
6.4
AND
Menu Item Selection
When a menu has been accessed the user can make available items appear on the
display using the UP-ARROW and DOWN-ARROW.
EXAMPLE D (SEE ALSO MENU MAP, SECTION 6.10).
To step through the CONFIGURATION menu, having gained access as described in
EXAMPLE C.
DISPLAY SHOWS
ACTION
1 [FP]
PRESS DOWN-ARROW
2 [Edit.P]
PRESS DOWN-ARROW
3 [Ecn]
PRESS DOWN-ARROW
4 [Gain]
PRESS UP-ARROW
5 [Ecn]
PRESS UP-ARROW
6 [Edit.P]
PRESS UP-ARROW
7 [FP]
To select a displayed item, press ENTER. The resulting display depends on which item
has been selected. The action required once an item is selected depends on the item in
question. Examples of selection of items EDIT PASSWORDS and FILTER are given in the
following sections 6.6 and 6.7. Examples of selection of other items are given in Section 7,
Calibration and Section 9, Limits.
19
6.5
Front Panel
The item FP allows the user to switch the front panel OFF or ON. Switching the front
panel ON allows access to all the normal run-time push button functions (i.e. changing the
display mode, zero etc.). Switching the front panel OFF disables all normal run-time push
button functions except the SETUP key.
When this item is selected, the user enters a sub-menu comprising two possible options
(ON and OFF), The UP-ARROW and DOWN-ARROW keys allow the user to step through
this sub-menu. When the required value is displayed, pressing the ENTER key selects the
displayed value and exits the sub-menu. Alternatively, pressing the RESET key exits the
sub-menu without changing the filter value. In either case the display will then show
[EDIT.P] (Edit Passwords), the next item in the CONFIGURATION menu.
6.6
Edit Passwords
First time users should make themselves generally familiar with the unit before
attempting to select the EDIT PASSWORDS item. Incorrect actions could result in
the user being locked out of the CONFIGURATION menu.
EDIT PASSWORDS allows the user to change the passwords from the default values
noted in section 6.1. This allows programmed features to be protected by passwords that
suit the user.
When this item is selected, the user enters a sub-menu with three items P1, P2 and P3.
UP-ARROW and DOWN-ARROW allow the user to step through this sub-menu. When the
required item is displayed, pressing ENTER selects that item. The display now shows a
number entry prompt with the existing password value. The password can be changed to
the required new value as described in general in Section 6.3.
EXAMPLE E (THIS IS NOT RECOMMENDED FOR FIRST TIME USERS)
TO CHANGE THE CALIBRATION MENU PASSWORD (P2) FROM 00002 TO 00010, HAVING
GAINED ACCESS TO THE CONFIGURATION MENU AS PREVIOUSLY DESCRIBED IN EXAMPLE C.
DISPLAY
ACTION
SHOWS
1
2
3
4
5
6
7
8
[FP]
[Edit.P]
[P1]
[P2]
00002
00000
00000
00010
PRESS DOWN-ARROW
PRESS ENTER TO SELECT EDIT PASSWORDS
PRESS UP-ARROW
PRESS ENTER TO SELECT PASSWORD 2
PRESS DOWN-ARROW TWICE
PRESS ENTER TO STEP TO NEXT DIGIT
PRESS UP-ARROW
PRESS ENTER & RESET SIMULTANEOUSLY TO ENTER
VALUE
9
PRESS RESET TO EXIT SUB-MENU
[P3]
10 [Ecn]
(AN UNDERLINED DIGIT REPRESENTS A FLASHING DIGIT)
20
NEW PASSWORD
6.7
Filter
The item FILTER allows the user to adjust the –3db point of the digital low pass filter. The
digital filtering acts on the display and serial output, but has no effect on the analogue
output. The digital low pass filter has nine possible cut off frequencies (-3db point) as
shown below.
FILTER VALUE
1
2
3
4
5
6
7
8
9
CUT OFF FREQUENCY (-3db)
100 Hz
75 Hz
50 Hz
25 Hz
10 Hz
7.5Hz
5.0Hz
2.5Hz
1.0Hz
Filter values 6-9
are only applicable
to instrument mod.
status 8 onwards
When this item is selected the user enters a sub-menu comprising the five possible filter
values shown above. The UP-ARROW and DOWN-ARROW keys allow the user to step
through this sub-menu. When the required value is displayed, pressing ENTER selects the
displayed value and exits the sub-menu. Alternatively, pressing RESET exits the submenu without changing the filter value. In either case the display will then show [COUNT]
(Count facility), the next item in the USER SETUP menu.
EXAMPLE F
TO CHANGE FILTER VALUE FROM 4 TO 5, HAVING GAINED ACCESS TO THE
CONFIGURATION MENU AS DESCRIBED IN EXAMPLE C.
1
2
3
4
5
6.8
DISPLAY SHOWS
[FP]
[Filt]
[Filt.4]
[Filt.5]
[Count]
ACTION
PRESS DOWN-ARROW UNTIL [FILT] IS DISPLAYED
PRESS ENTER TO SELECT FILTER
PRESS UP-ARROW TO CHANGE VALUE
PRESS ENTER TO SELECT VALUE 5
Count Facility
(Only applicable to instruments mod. status 8 onwards)
This facility allows you to enter a number which will force the calibrated input signal to be
displayed in the specified resolution. For example, if the display resolution is 2 decimal
places and 25 is entered, then the calibrated input signal will be displayed in increments of
0.25 (e.g. 0.00, 0.25, 0.50, etc.). Example G details how to change the count value.
Notes – The count facility only applies to the displayed input signal and does not
apply to:
1.
2.
3.
The cal. signal (i.e. AC excitation voltage, displayed shunt cal. value)
Signal used for the software limits or the MAX/MIN/TIR values.
Data printed to the RS232/485 port.
21
Example G
Changing the number of counts having gained access to the CONFIGURATION menu as described in
Example C
Display Shows
Actions
1
[FP]
Press DOWN-ARROW until [Filt] is displayed.
2
[Count]
Press ENTER to edit the number of counts
3
[00000]
Enter the required number of counts (see 6.3)
5
[L1-4]
6.9
Returning To Normal Operating Mode
When the display is showing any of the options in the first level of the CONFIGURATION,
CALIBRATION or USER SETUP menus, it is possible to return to the normal operating
mode by either of two actions.
1)
2)
Press RESET.
Press the DOWN-ARROW key until the display shows [run] and then press the
ENTER key.
In both cases the display will be blanked and an increasing bar from left to right will be
displayed to indicate that the E725 is saving the setup parameters.
6.10
Menu Map
EXAMPLE A
See Section 6.2 for menu access
- REMINDER
TO
ACCESS A MENU FROM THE UNIT'S NORMAL OPERATING MODE, PRESS THE SETUP KEY FOR
AT LEAST ONE SECOND. THE DISPLAY WILL SHOW THE PROMPT [UL 1]. PRESS THE MODE KEY
TO STEP THROUGH THE VARIOUS OPTIONS, WHICH ARE:-
DISPLAY
[UL 1]
[UL 2]
[UL 3]
ACCESS
USER SETUP MENU
CALIBRATION AND USER SETUP MENU
CONFIGURATION, CALIBRATION AND USER SETUP MENU
WHEN
THE REQUIRED USER LEVEL IS DISPLAYED, PRESS THE LIMITS KEY TO SELECT THE
DISPLAYED OPTION. THE DISPLAY WILL NOW SHOW A NUMBER ENTRY PROMPT [00000] WITH THE
LAST DIGIT FLASHING. AT THIS POINT THE RELEVANT PASSWORD SHOULD BE ENTERED (SEE
SECTION 6.3 FOR NUMBER ENTRY.)
22
PASSWORD
P3
P2
P1
DISPLAY MENU ITEM
[FP]
[Edit.P]
[Ecn]
[GAin]
[dP]
[CAL.IP]
[LIN.IP]
[E.OFF]
[t.Pt]
[FILt]
[Count]
[L 1-4]
[L 1-2]
[rUN]
Switch front panel ON/OFF
Edit Passwords
Excitation Voltage
Gain Range
Decimal Point
Calibrate Input
Linearise Input (If applicable)
Engineering Offset
Tare Point
Filter
Count Facility
Limits setup (standard)
Limits setup (fast limit option
Normal operating mode)
7
CALIBRATION
7.1
Calibration Overview
MANUAL
REFERENCE
See Section 6.5
See Section 6.6
See Section 7.2
See Section 7.3
See Section 7.3
See Section 7.4
See Section 7.5
See Section 7.6
See Section 7.7
See Section 6.7
See Section 6.8
See Section 9
See Section 9
See Section 6.9
The E725 can operate with a wide range of transducers. Calibration is a procedure,
involving an E725 and a transducer, to set up the E725 to read correctly in engineering
units (e.g. bar) as required.
For example, when using an E725 with a pressure transducer, the user may want to see a
display of 0 to 100.0 over a pressure range of 0 to 100 bar. This is achieved through
calibration.
One of several possible approaches to the above example could be to apply 0 bar to the
transducer and programme the E725 to display 0.0 at this pressure, then apply 100 bar to
the transducer and programme the E725 to display 100.0 at this pressure.
This section describes procedures, including programming, for the calibration of a single
transducer. If the E725 is fitted with Option 2DC1, 2DC2 or 2DC3 a second channel is
available. Details for the calibration of the second channel are given in Section 11.
The E725 has an analogue output, calibration of this is dealt with in Section 8.
The E725 is capable of compensating for transducer non-linearity using either multi-point
or polynomial techniques. It is anticipated that many users will not require these facilities,
therefore they are covered in separate documentation.
It is possible that the E725 has been supplied calibrated for use with a specific
transducer. In this case calibration should not be necessary and care should be
taken not to erase existing calibration data.
23
7.2
Excitation Voltage
Almost all transducers require an input voltage. This is generally called "excitation" in the
case of unamplified strain gauge transducers, and "supply voltage" in the case of amplified
transducers. The E725 can work with a wide range of transducers. A variety of excitation
and supply voltage arrangements are possible.
This section deals with excitation voltage available at pins 1 and 2 of the 9-pin D-type
transducer connector (see Section 5). Excitation and supply voltage connections could
involve other pins on this connector. This section is only relevant if pins 1 and/or 2 are to
be used.
The excitation voltage on pins 1 and 2 is user selectable to 1.5, 3, 5 or 10 V nominal. This
voltage is bipolar, e.g. if the excitation is set to 10 V, then pin 1 will be at +5 V and pin 2
will be at -5 V with respect to 0 V (ground).
For many re-calibrations or calibrations of replacement transducers, it may not be
necessary to change the excitation voltage. The existing voltage level will probably apply
in the new situation. For this reason the item EXCITATION is on the CONFIGURATION
rather than the CALIBRATION menu.
However, in general, the excitation voltage will need to be set to suit the transducer being
calibrated. This must be done before starting the main calibration procedure (see Section
7.5).
To establish the correct excitation voltage, refer to the transducer manufacturer's datasheets or calibration sheets. In the case of unamplified strain gauge transducers it is
usually best to set the excitation voltage to the maximum level allowed by the
manufacturer.
IT IS VERY IMPORTANT THAT THE EXCITATION VOLTAGE PROVIDED BY THE E725
DOES NOT EXCEED THE MAXIMUM ALLOWED FOR THE TRANSDUCER. For this
reason the default setting for EXCITATION VOLTAGE is 1.5 V, the minimum possible.
Also, it is recommended that the transducer is disconnected before the item EXCITATION
is selected, since the voltage displayed on the E725 during programming is actually
present on the pins.
To change the excitation voltage it is necessary to understand E725 programming. The
user should have read Section 6.
CHANGING EXCITATION WILL ERASE EXISTING CALIBRATION DATA.
When the item EXCITATION in the CONFIGURATION menu is selected, the user enters a
sub-menu comprising the four possible excitation values shown in volts. UP-ARROW and
DOWN-ARROW allow the user to step through this sub-menu. When the required voltage
is displayed, pressing ENTER selects that voltage and exits the sub-menu. Alternatively,
pressing RESET exits the sub-menu without changing the range. In either case the display
will then show [GAIN], the next item in the CONFIGURATION menu.
24
EXAMPLE H
TO CHANGE THE EXCITATION FROM 1.5V TO 3V, HAVING GAINED ACCESS TO THE
CONFIGURATION MENU AS DESCRIBED IN EXAMPLE C IN SECTION 6.3
1
2
3
4
5
7.3
DISPLAY SHOWS
[FP]
[Ecn]
[Ecn.1.5]
[Ecn.3]
[Gain]
ACTION
PRESS DOWN-ARROW TWICE
PRESS ENTER TO SELECT EXCITATION
PRESS UP-ARROW TO CHANGE VOLTAGE
PRESS ENTER TO SELECT 3V.
Gain Range
The E725 can accept a full-scale signal in a band from ±0.003 to ±10.0 V. This band is
divided into eight ranges numbered 1 to 8.
For many re-calibrations or calibrations of replacement transducers, it may not be
necessary to change the gain range. The existing gain range will probably apply in the new
situation. For this reason the item GAIN is on the CONFIGURATION rather than the
CALIBRATION menu.
However, in general, the gain range will need to be set to suit the transducer being
calibrated. This must be done before starting the main calibration procedure (see Section
7.5).
The required gain range setting depends on the full-scale signal input to the E725 (i.e. the
full-scale output from the transducer).
Typically, manufacturers' data sheets or calibration certificates state transducer full scale
output (in V) or sensitivity (in mV/V). The sensitivity relates output at full scale to excitation
voltage.
FOR EXAMPLE I THE CORRECT GAIN RANGE IS 6.It may be necessary to calculate the fullscale output from the sensitivity figure (sometimes referred to as the calibration factor on
manufacturers' calibration sheets).
EXAMPLE I
CALCULATE TRANSDUCER FULL-SCALE OUTPUT FOR A TRANSDUCER, GIVEN A
MANUFACTURER’S CALIBRATION FACTOR OF 2.9964MV/V & A MAX. ALLOWED EXCITATION OF 10V
TO
FULL SCALE OUTPUT = CALIBRATION FACTOR X EXCITATION
= 2.9964 X 10
= 29,964MV
(IT IS ASSUMED HERE THAT E725 EXCITATION HAS BEEN SET TO 10V)
The transducer full scale output is the full scale input to the E725. The following table
relates gain range to full scale input.
25
GAIN RANGE
1
2
3
4
5
6
7
8
FULL-SCALE INPUT (V)
3.0
to
10.0
1.0
to
3.0
0.3
to
1.0
0.1
to
0.3
0.03
to
0.1
0.01
to
0.03
0.003
to
0.01
0.0025
to
0.003
For 4 to 20mA input signals using a 10 Ohm load resistor (see Sections 5.5 & 5.6) the
correct gain range is 4.
FOR EXAMPLE I THE CORRECT GAIN RANGE IS 6.
To change the gain range it is necessary to understand E725 programming. The user
should have read Section 6.
CHANGING GAIN RANGE WILL ERASE EXISTING CALIBRATION DATA.
When the item GAIN in the CONFIGURATION menu is selected, the user enters a submenu comprising the eight possible gain ranges. UP-ARROW and DOWN-ARROW allow
the user to step through this sub-menu. When the required range is displayed, pressing
ENTER selects that range and exits the sub-menu. Alternatively, pressing RESET exits
the sub-menu without changing the range. In either case the display will then show [DP]
(DECIMAL POINT), the first prompt in the CALIBRATION menu.
Exiting the sub-menu via the ENTER key (as opposed to the RESET key) will erase
existing calibration data, even if the gain range has not been changed.
EXAMPLE J
To change the GAIN RANGE from 1 to 2, having gained access to the CONFIGURATION
menu as described in Example C (Section 6.3)
1
2
3
4
5
7.4
DISPLAY SHOWS
ACTION
[FP]
[GAin]
[GAin.1]
[GAin.2]
[dP]
PRESS DOWN-ARROW THREE TIMES
PRESS ENTER TO SELECT GAIN
PRESS UP-ARROW TO CHANGE GAIN RANGE
PRESS ENTER TO SELECT RANGE 2
Decimal Point
Before starting the main calibration procedure (see Section 7.5) it is necessary to set the
position of the decimal point. This will define the number of decimal places displayed when
in normal operating mode.
To do this it is necessary to understand E725 programming. The user should have read
Section 6.
26
CHANGING DECIMAL POINT WILL ERASE EXISTING CALIBRATION DATA AND LIMIT
CONFIGURATION.
When the item DECIMAL POINT in the CALIBRATION menu is selected, the display
shows 00000 with the decimal point in its existing position. Its position can be shifted to the
left or right by pressing UP-ARROW or DOWN-ARROW respectively. When the decimal
point is in the required position, pressing ENTER accepts that position. The user is
returned to the CALIBRATION menu, the display shows the next item [CAL.IP]
(CALIBRATE INPUT).
7.5
Calibrate Input
CALIBRATE INPUT is the menu item where the main calibration procedure must be
carried out. Before this procedure is started, the transducer must be connected to the
E725 (see Section 5), the excitation voltage must be programmed (if applicable, see
Section 7.2), the gain range must be programmed (see Section 7.3) and the decimal point
position must be programmed (see Section 7.4).
For optimum performance the E725 should be allowed to warm up (with excitation or
supply voltage applied to the transducer) for at least twenty minutes before calibration.
The user must establish what display arrangement is required. For example, if the
transducer in question is a ±250 lbs. tension/compression load cell, the E725 may be
required to display ±250.0 lbs., ±113.5 kg, ±1112 N etc.
If a direct calibration is to be performed, the user must decide on the calibration point. This
may be the same as the transducer full scale, but it may be less. For example, if a user
plans to use a ±250 lbs. load cell over a range of ±150 lbs., never exceeding 150 lbs. in
tension or compression, it would be reasonable to choose a calibration point of 150 lb.
If a shunt calibration is to be performed, the user must calculate a calibration point from
data given on the transducer calibration sheet. This calculation is dealt with within
EXAMPLE K .
Here is a checklist for what the user must decide.
Engineering units
e.g. Kg
Display full scale
e.g. 100 Kg
Display resolution
e.g. 100.0 Kg
Display polarity
e.g. ±100.0 Kg, positive in tension
Calibration zero point
e.g. 0 displayed at zero load.
Calibration point
(This is a user decision for direct calibrations, it must be
calculated for shunt calibrations, see EXAMPLE K).
To perform a calibration it is necessary to understand E725 programming, The user should
have read Section 6.
27
When the item CALIBRATE INPUT in the CALIBRATION menu is selected, the display
shows a number entry prompt. This is the value of the calibration point and can be edited
as described in general in Section 6.3. Pressing ENTER or ENTER and RESET together
(as appropriate) selects the value displayed. The E725 enters CALIBRATION MODE, the
display shows a transducer reading in counts or engineering units (depends on whether
the E725 was already calibrated).
In CALIBRATION MODE, the front panel keys take on specific functions.
MODE and ZERO together
Clears any previous calibration.
ZERO
Fixes the calibration zero point.
ENTER
Takes a cal reading (positive or negative) for bipolar cal.
SETUP
MODE and ENTER together
MODE and SETUP together
Scales the transducer reading.
Performs a shunt calibration.
Accepts the calibration and exits CALIBRATION MODE.
The display will then show E.OFF, the next relevant item
in the CALIBRATION menu.
If it is necessary (e.g. due to an error) to exit CALIBRATION MODE and re-start the main
calibration procedure, press MODE and SETUP together. The display shows [E.OFF]
(ENGINEERING OFFSET). Press UP-ARROW as required to display item CALIBRATE
INPUT, press ENTER to select CALIBRATE INPUT and proceed as before.
-
*1
*2
*3
*4
*5
*6
NOTES REGARDING DISPLAY IN EXAMPLES K, L AND M
IN THE FOLLOWING EXAMPLES THE "DISPLAY SHOWS" COLUMN SHOWS THE ACTUAL
CHARACTERS THAT WILL APPEAR EXCEPT WHERE MARKED AS FOLLOWS:ANY NUMBER MAY APPEAR (IN COUNTS OR ENGINEERING UNITS).
THE DISPLAY WILL READ TRANSDUCER OUTPUT IN UNCALIBRATED COUNTS. A DISPLAY
GREATER THAN 55000 OR LESS THAN -55000 INDICATES A PROBLEM. CHECK CONNECTIONS
AND GAIN SETTING.
SYSTEM NOISE MAY CAUSE SLIGHT FLUCTUATION ABOUT THE READING SHOWN IN THE
EXAMPLE
A DISPLAY OF BETWEEN ±16666 AND ±55000 COUNTS CONFIRMS CORRECT GAIN RANGE
SETTING.
AT THIS STAGE THE ACTUAL APPLIED LOAD (OR PRESSURE ETC) IS DISPLAYED.
RECOMMENDED FULL SCALE IS 50000 WITH OVERRANGE CAPABILITY OF 10% I.E. TO 55000.
28
EXAMPLE K – BIPOLAR DIRECT CALIBRATION
TO CALIBRATE A ±250 LB. TENSION/COMPRESSION LOAD CELL TO DISPLAY ±100.0 KG USING A BIPOLAR
DIRECT LOAD TECHNIQUE (±100 KG APPLIED BY UNIVERSAL TESTING MACHINE).
1
2
3
ACCESS CONFIGURATION MENU (EXAMPLE C IN SECTION 6.3).
CHANGE EXCITATION IF NECESSARY (SECTION 7.2).
CHANGE GAIN RANGE IF NECESSARY (SECTION 7.3).
STEPS 1 TO 3 ARE NOT NECESSARY IN SOME SITUATIONS (E.G. RE-CALIBRATIONS). IF STEPS 1 TO 3 ARE
TAKEN, THE USER IS AUTOMATICALLY GIVEN ACCESS TO THE CALIBRATION MENU. IF NOT, ACCESS
CAN BE VIA PASSWORD P2 (EXAMPLE C IN SECTION 6.3 APPLIES IN GENERAL).
ACTION
DISPLAY SHOWS
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
[dP]
[00000]
[00000]
[CAL.IP]
[00000]
[00000]
[01000]
[1234]
[19]
[0]
[34567]
[34567]
[-34678]
[-34678]
[- 100.0]
[E.OFF]
*1
*2
*3
*4
*4
*4
*4
*5
PRESS ENTER TO SELECT ITEM DECIMAL POINT.
PRESS UP-ARROW TO SHIFT DECIMAL POINT
PRESS ENTER TO ACCEPT DECIMAL POINT POSITION
PRESS ENTER TO SELECT CALIBRATE INPUT
PRESS ENTER 3 TIMES (EDITING CAL PT)
PRESS UP-ARROW (EDITING CAL PT)
PRESS ENTER AND RESET TOGETHER (ACCEPTS CAL PT)
PRESS MODE AND ZERO TOGETHER (CLEARS PREVIOUS CAL)
APPLY ZERO LOAD TO THE LOAD CELL AND PRESS ZERO
APPLY 100KG TENSION TO THE LOAD CELL
PRESS ENTER
APPLY 100KG COMPRESSION TO THE LOAD CELL
PRESS ENTER
PRESS SETUP (ACTUAL LOAD NOT IMPORTANT HERE)
PRESS MODE AND SETUP TOGETHER
IF NO OTHER MENU ITEMS ARE REQUIRED, EXIT THE CALIBRATION
MENU BY
PRESSING RESET. AFTER A 2 SECOND DELAY, THE UNIT WILL GO TO
NORMAL OPERATING MODE.
SEE IMPORTANT NOTE AT END OF SECTION 7.5
*1, *2 ETC., SEE NOTE ABOVE HEADED "NOTES REGARDING DISPLAY IN EXAMPLES K, L, AND
M".
29
EXAMPLE L – UNIPOLAR DIRECT CALIBRATION
TO
CALIBRATE A 3000 PSIG PRESSURE TRANSDUCER TO DISPLAY 0 TO 3000 PSIG USING A
UNIPOLAR DIRECT PRESSURE TECHNIQUE (3000 PSIG APPLIED BY DEAD-WEIGHT TESTER). STEPS
1, 2 AND 3 PLUS ASSOCIATED COMMENT ARE AS ABOVE EXAMPLE K.
DISPLAY SHOWS
ACTION
4
PRESS DOWN-ARROW (SKIP DECIMAL POINT)
[dP]
5
PRESS ENTER TO SELECT CALIBRATE INPUT
[CAL.IP]
6
PRESS ENTER THREE TIMES (EDITING CAL.PT)
00000
7
PRESS UP-ARROW THREE TIMES (EDITING CAL.PT)
00000
8
PRESS ENTER & RESET SIMULTANEOUSLY (ACCEPTS CAL.PT)
03000
1
9
PRESS MODE & ZERO TOGETHER (CLEARS PREVIOUS CAL) *
[2345]
2
10
APPLY ZERO PRESSURE, PRESS ZERO *
[21]
3
11
APPLY 3000 PSIG *
[0]
4
12
PRESS SETUP *
[43210]
5
13
PRESS MODE & SETUP SIMULTANEOUSLY *
[3000]
14
IF NO OTHER MENU ITEMS ARE REQUIRED, EXIT THE CALIBRATION
[E.OFF]
MENU BY PRESSING RESET. AFTER A 2 SECOND DELAY, THE UNIT
WILL GO TO NORMAL OPERATING MODE.
SEE IMPORTANT NOTE AT END OF EXAMPLE I.
*1,
*2,
ETC.-SEE NOTE ABOVE HEADED “NOTES REGARDING DISPLAY IN EXAMPLES K, L
AND M.”
30
EXAMPLE K - SHUNT CALIBRATION
POINTS TO NOTE REGARDING SHUNT CALIBRATION.
1) SHUNT CALIBRATIONS ARE APPLICABLE TO MOST (BUT NOT ALL) TYPES OF UNAMPLIFIED
STRAIN GAUGE TRANSDUCERS. THEY ARE NOT APPROPRIATE FOR OTHER TYPES OF
TRANSDUCER USED WITH THE E725.
2) THE TECHNIQUE INVOLVES THE E725 INTERNALLY CONNECTING A SHUNT RESISTOR ACROSS
ONE ARM OF THE TRANSDUCER'S STRAIN GAUGE BRIDGE. THIS PRODUCES A TRANSDUCER
OUTPUT THAT CAN BE USED AS A CALIBRATION REFERENCE.
3) THE INTERNAL RESISTOR VALUE IS 59K OHM. IN SOME CASES IT MAY BE NECESSARY TO
CHANGE THIS RESISTOR TO ACHIEVE AN APPROPRIATE TRANSDUCER OUTPUT.
INSTRUCTIONS FOR THIS PROCEDURE ARE AVAILABLE ON REQUEST
4) A PARTICULAR TRANSDUCER CONNECTION ARRANGEMENT IS NECESSARY IF A SHUNT
CALIBRATION IS TO BE USED (SEE SECTION 5.2).
TO CALIBRATE A 3000 PSIG PRESSURE TRANSDUCER TO DISPLAY 0 TO 200.0 BAR G USING A
SHUNT CALIBRATION TECHNIQUE, WHERE THE MANUFACTURER'S CALIBRATION CERTIFICATE FOR
THE TRANSDUCER STATES THE FOLLOWING.
CAPACITY
CALIBRATION FACTOR
3000 PSIG
2.9964
MV/V
SHUNT CAL FACTOR
SHUNT RESISTOR
1.4385 MV/V
59K OHM
CALCULATION OF CALIBRATION POINT
CP = SCOP X TFS
FSOP
WHERE
CP
=
CALIBRATION POINT
SCOP
=
SHUNT CAL. OUTPUT
FSOP
=
FULL SCALE OUTPUT
TFS
=
TRANSDUCER FULL SCALE
The Shunt Cal. Output is given on the transducer calibration certificate, it is sometimes
referred to as "Shunt Cal Factor". (usually expressed in mV or mV/V)
THE FULL SCALE OUTPUT
IS GIVEN ON THE TRANSDUCER CALIBRATION CERTIFICATE, IT IS
SOMETIMES REFERRED TO AS "CALIBRATION FACTOR". IT IS USUALLY EXPRESSED IN MV OR MV/V.
IN THE ABOVE EQUATION, SHUNT CAL. OUTPUT AND FULL SCALE OUTPUT MUST BE IN THE SAME
ENGINEERING UNITS (E.G. BOTH BE IN MV/V).
THE TRANSDUCER FULL SCALE IS GIVEN ON THE TRANSDUCER CALIBRATION CERTIFICATE, IT IS
SOMETIMES REFERRED TO AS "CAPACITY". IT MAY BE NECESSARY TO CONVERT THE ENGINEERING
UNITS OF THIS VALUE. IN FACT THIS IS THE CASE IN OUR EXAMPLE. THE TRANSDUCER FULL SCALE
IS 3000 PSIG, SINCE THE E725 IS REQUIRED TO DISPLAY IN BAR G, 3000 PSIG MUST BE
CONVERTED TO BAR G. COMMON CONVERSION FACTORS ARE GIVEN IN SECTION 15. THE
TRANSDUCER FULL SCALE BECOMES 206.84 BAR G.
THE SHUNT RESISTOR VALUE IS NOT USED
OHM FOR THE CALCULATION TO BE VALID.
IN THE EXAMPLE CALCULATION, BUT IT MUST BE
59K
RETURNING TO THE PREVIOUS EQUATION.
CP = 1.4385 X 206.84
2.9964
= 99.3 BAR G
EXAMPLE K CONTINUES ON NEXT PAGE
31
EXAMPLE K - SHUNT CALIBRATION CONTINUED
PROGRAMMING STEPS.
STEPS 1, 2 AND 3 PLUS ASSOCIATED COMMENT ARE AS ABOVE EXAMPLE K.
4
5
6
7
8
9
10
11
12
13
14
15
16
DISPLAY
SHOWS
[DP]
[00000]
[0000.0]
[CAL.IP]
[0000.0]
[0000.3]
[0000.3]
[0009.3]
[0009.3]
[0099.3]
[345]
[23]
[0]
ACTION
*1
*2
*3
3
17
[99.3]
*
18
19
[0.0]
[E.OFF]
*5
PRESS ENTER TO SELECT ITEM DECIMAL POINT
PRESS UP-ARROW TO SHIFT DECIMAL POINT
PRESS ENTER TO ACCEPT DECIMAL POINT POSITION
PRESS ENTER TO SELECT CAL.IP
PRESS UP-ARROW THREE TIMES (EDITING CAL PT)
PRESS ENTER (EDITING CAL PT)
PRESS UP-ARROW NINE TIMES (EDITING CAL PT)
PRESS ENTER (EDITING CAL PT)
PRESS UP-ARROW NINE TIMES (EDITING CAL PT)
PRESS ENTER & RESET TOGETHER (ACCEPTS CAL PT)
PRESS MODE & ZERO TOGETHER (CLEARS PREVIOUS CAL)
APPLY ZERO PRESSURE, PRESS ZERO
MAINTAIN ZERO PRESSURE, PRESS MODE & ENTER TOGETHER
TO PERFORM SHUNT CALIBRATION
FOR APPROXIMATELY FIVE SECONDS, THE DISPLAY READS THE
TRANSDUCER OUTPUT WHILE THE SHUNT RESISTOR IS IN CIRCUIT.
NO ACTION IS REQUIRED FOR THE DISPLAY TO REVERT TO
NORMAL.
PRESS MODE & SETUP TOGETHER
IF NO OTHER MENU ITEMS ARE REQUIRED, EXIT THE CALIBRATION
MENU BY PRESSING RESET. AFTER A 2 SECOND DELAY, THE UNIT
WILL GO TO NORMAL OPERATING MODE. SEE IMPORTANT NOTE
AT END OF SECTION 7.5
*1, *2 ETC., SEE NOTE ABOVE HEADED "NOTES REGARDING DISPLAY IN EXAMPLES K, L, AND
M".
IMPORTANT NOTE
Calibration menus should only be re-accessed by appropriate personnel.
Subsequent errors in these menus could lead to a need for re-calibration.
32
7.6
Shunt Calibration as A Calibration Check
Whether the original calibration is performed using a direct or shunt technique, the shunt
calibration feature can often be used as post calibration check. This applies to most types
of unamplified strain gauge transducer, connected as "With Shunt Calibration" in Section
5.2.
Any display offset that has previously been applied (via ZERO key or digital input) will
confuse the shunt function so press RESET and ZERO to remove any display offset.
When the E725 is in normal operating mode, pressing MODE and LIMITS together brings
the shunt resistor into circuit for about five seconds, the number displayed will increase by
an amount called the shunt calibration reading. Therefore the shunt cal reading is equal to
the display with shunt cal, minus the display without the shunt cal. After five seconds, the
display reverts to normal reading.
This operation should be performed when the transducer is measuring a static quantity
(most conveniently, zero but do not press ZERO as this may confuse the calculation).
The shunt calibration value should change very little over time. If the value differs largely
from the expected value, the system should be checked.
7.7
Linearise Input
This item is not present in all versions of the E725, i.e. if Lin IP not displayed.
The E725 is capable of compensating for transducer non-linearity using either multi-point
or polynomial techniques. The item [LIN.IP] (LINEARISE INPUT) relates to multi-point
linearisation. It is anticipated that many users will not require this facility, therefore it is
covered in separate documentation (RDP Reference CD1426).
If [LIN.IP] (LINEARISE INPUT) is selected accidentally the display shows the transducer
signal in counts or engineering units (depends on calibration status of E725). The user
should exit by pressing the MODE and SETUP keys together. The display will then
show[E.OFF], the next item in the CALIBRATION menu.
7.8
Engineering Offset
The item [E.OFF] (ENGINEERING OFFSET) in the CALIBRATION menu allows an
engineering offset to be added to the calibrated transducer signal. For example, if a
transducer has been calibrated to read ±1000 g and the ENGINEERING OFFSET is set to
+100, in normal operating mode the display will read -900 to +1100 g.
The ENGINEERING OFFSET is not the same as the CALIBRATION OFFSET, which is
fixed during the main calibration procedure (see Section 7.5).
The ENGINEERING OFFSET is not the same as the ZERO DISPLAY function, which is
applied via the ZERO key or equivalent digital input (see Sections 4.2 and 4.3).
If an ENGINEERING OFFSET has been programmed, when in normal operating mode the
function of the ZERO key (or equivalent digital input) will be to set the display to the value
33
of the ENGINEERING OFFSET (assuming the tare point has not been used to override
this, see Section 7.9).
To change the engineering offset it is necessary to understand E725 programming. The
user should have read Section 6.
When the item [E.OFF] (ENGINEERING OFFSET) in the CALIBRATION menu is selected,
the display shows a number entry prompt. The value is edited as described in general in
Section 6.3. Pressing ENTER or ENTER and RESET together (as appropriate) selects the
value displayed. The user is returned to the CALIBRATION menu, the display shows the
next item, [t.Pt] (TARE POINT).
7.9
Tare Point
The item [t.Pt] (TARE POINT) in the CALIBRATION menu allows a tare point to be
defined. The tare point is the reading obtained in normal operating mode when the ZERO
key is pressed (or the equivalent digital input is applied).
The default value for the tare point is 0, i.e. when in normal operating mode, pressing the
ZERO key sets the display to 0. If an engineering offset is programmed, the tare point is
automatically set to the value of the engineering offset.
For example, if a transducer has been calibrated to read ±1000 g and the ENGINEERING
OFFSET is set to +100, in normal operating mode the display will read -900 to +1100 g.
The tare point is automatically set to +100, so pressing the ZERO key sets the display to
+100.
It may be necessary to override the arrangement described above. For example, if it is
required that a ZERO key operation sets the display to 0 rather than +100, this can be
achieved by changing the tare point value to 0.
To change the TARE POINT it is necessary to understand E725 programming. The user
should have read Section 6.
When the item [t.Pt] (TARE POINT) in the CALIBRATION menu is selected, the display
shows a number entry prompt. The value is edited as described in general in Section 6.3.
Pressing ENTER or ENTER and RESET together (as appropriate) selects the value
displayed. The display shows [L 1-4] which is the first item in the LIMITS menu.
34
8
ANALOGUE OUTPUT
8.1
Analogue Output Description
The E725 has an analogue output of both voltage (up to ±10V) and current (4-20mA). The
output is independent of the microprocessor controller and therefore is unaffected by
ZERO commands.
The 4 to 20mA output is set up to give 4mA at a transducer signal of zero. Therefore it is
not appropriate to use 4 to 20mA output for bipolar applications (e.g. tension/compression
load cells and bipolar pressure transducers). It is recommended that a ±10V output is used
for bipolar applications.
Where the E725 has two input channels, the analogue output represents whichever
channel or function has been selected for display (see Section 11).
The analogue output is adjusted using the zero and gain screwdriver potentiometers on
the rear panel. These are located at the bottom left of the rear panel and are marked 'Z'
and 'G'. The zero and gain potentiometers are common to both the voltage and the 420mA output. Therefore, although both may be connected and used, only one can be
accurately set up. The zero and gain potentiometers only affect the analogue output, they
have no effect on the display.
8.2
Analogue Output Connections & Specification
The analogue output mating connector is a 3.5mm diameter, 19mm long stereo jack-plug.
The socket is located at the bottom left of the rear panel. The connections are as follows:
CONTACT
1
2
3
FUNCTION
4-20mA
±10V
0V (COMMON) & Shield
Specification
Analogue output (short circuit proof)
0 to ±10V (at 5mA max) AND 4-20mA into 0 to
500 Ohms
Analogue output bandwidth
0 to 300Hz
Analogue output ripple (P-P typical) Voltage:
2µV (RTI) + 2mV (RTO)
4-20mA:
3nA (RTI) + 30µA (RTO)
General specification may also be relevant. See Section 13.
8.3
Analogue Output Calibration
The reason for calibrating the analogue output is to ensure that the relationship between
the force/pressure etc applied to the transducer and the analogue voltage or current output
is as required. (E.g. 0 to 10V for zero to full scale on the transducer). The E725 must be
calibrated as described in Section 7 (this may have been done by RDP) before the
analogue output is calibrated. The E725 display can then be used in the process of
calibrating the analogue output.
35
In order to calibrate the analogue output either a physical input or a bridge shunt must be
applied to the transducer connected to the E725. The analogue output must be monitored
using a voltmeter or milliammeter depending on the required output (volts or 4-20mA).
The process described in Section 7.3 will have set the gain range for the analogue output.
If the
gain range value has not been correctly entered, the analogue output may not operate
over the full ±10V or 4-20mA range.
To calibrate the analogue output first ensure there is zero load/pressure etc applied to the
transducer and adjust the zero (Z) control until the output is measured at 0V (or 4mA for 420mA output).
Then EITHER
1)
OR
2)
Apply a known force/pressure etc. to the transducer and adjust the gain (G) control
until the output is as required. It is appropriate to use the value displayed on the
E725 to establish the force/pressure etc. applied to the transducer. The applied
force/pressure etc. should ideally be between 50% and 100% of full-scale
FOR CERTAIN UNAMPLIFIED STRAIN GAUGE TRANSDUCERS ONLY.
Check the transducer is appropriately connected as shown in "With shunt
calibration" in Section 5.2
Activate the CAL function (by pressing MODE & CAL together). Adjust the analogue
output required for the momentary display achieved. (The CAL function
automatically switches off after a few seconds so it will need to be repeatedly
activated).
EXAMPLE 1, VOLTAGE OUTPUT
If the following were true.
Transducer full scale:500 units
Analogue output required at full scale:- 10V
Momentary shunt cal value displayed:- 237.3
Then the voltage output during the cal operation should be (237.3/500) x 10V = 4.75V
EXAMPLE 2, 4 to 20 mA OUTPUT (other detail as for example 1)
For the same transducer, a 4-20mA output is required then the output is
((237.3/500) X 16mA) + 4mA = 11.6mA.
4 to 20mA output is only suitable for unipolar transducers, or bipolar transducers used in
unipolar mode.
Note: Reversing transducer connections will reverse analogue outputs irrespective of
display programming.
36
9
LIMITS
9.1
Limits Description
The E725 has as standard four Limits. A limit (sometimes referred to as a trip limit or set
point) is a facility to indicate when the signal is above or below a certain value. On the
standard unit, the indication takes the form of a front panel LED and a TTL output signal
available from a rear panel connector.
There are several relay options available and your use of this section will depend on
whether you have any of the relay options fitted. Please check the part number of your
E725, it is located on a label on the top of the housing.
E725-NNN-NNN-XXX-N-N where XXX is important and NNN is not important here.
If XXX = R,
If XXX = RS,
If XXX = FR,
If XXX = FRS,
then the unit has 4 mechanical relays
then the unit has 4 solid state relays
then the unit has 2 fast mechanical relays
then the unit has 2 fast solid state relays
= Option R
= Option RS
= Option FR
= Option FRS
Any other value of XXX is not relevant to the LIMITS section and indicates that the E725
does not have any LIMIT options fitted, however, TTL outputs are available.
9.2
Connections and Specification
Connections for TTL outputs, i.e. no limit option fitted. TTL outputs are available via the
connector labelled DIGITAL I/O. Pin numbers are as follows: PIN
4
5
6
7
8
Description
Limit 1 TTL output (Low when front panel LED is OFF)
Limit 2 TTL output (Low when front panel LED is OFF)
Limit 3 TTL output (Low when front panel LED is OFF)
Limit 4 TTL output (Low when front panel LED is OFF)
Common for TTL outputs
Connections for the R, RS, FR and FRS options (9 pin D type marked OPTION)
PIN
Solid state relays
Mechanical relays (* see following)
Opt R
Opt FR
Opt RS
Opt FRS
1
2
Relay 1 pole*
Relay 1 common
Relay 1 (normally open)
Relay 1 common
Relay 1
Relay 1
Relay 1
Relay 1
3
4
5
6
7
8
9
Shell
Relay 2 pole*
Relay 2 common
Relay 1 (normally closed)
Relay 2 (normally open)
Relay 2 common
Relay 2 (normally closed)
L1 logic
Relay 2
Relay 2
Relay 3
Relay 3
Relay 4
N/A
Relay 2
Relay 2
N/A
L1 logic
Relay 4
N/A
L2 logic
Logic common (0V)
Relay 3 pole*
Relay 3 common
Relay 4 pole*
Relay 4 common L2 logic
N/A
Logic common (0V)
Cable shield / shield
37
*
For option R only, it is possible to select (see below) whether the relay is normally
open or normally closed. The default setting is normally open.
In NORMALLY OPEN operation, the relay contacts are OPEN CIRCUIT whilst the
front panel LIMIT light is OFF.
In NORMALLY CLOSED operation, the relay contacts are CLOSED CIRCUIT whilst
the front panel LIMIT light is OFF.
If you need to change the operation of the relays, it is necessary to change some switches
on the option card circuit board. This involves opening the case of the E725. Please follow
these instructions carefully.
Isolate the power to the E725. Remove all connectors from the rear panel. Undo the 4
screws on the rear panel (black crosshead located in each corner). Observe the necessary
precautions for handling static sensitive devices. Holding the power cable grommet, pull
until the circuit boards have withdrawn by about 75mm (3"). The switches are now in view
(looking from the top of the unit). Their function and position is shown below.
For NORMALLY OPEN
relay operation, the slider
switch should be in the
right-hand
position
(marked +)
For
NORMALLY
CLOSED relay operation,
the slider switch should
be in the left-hand
position (marked 0)
Specification of LIMITS for all versions.
Number of relays
Response time
Max voltage (dc)
Max voltage (ac)
Max switching
On resistance
Off resistance
Accuracy
Hysteresis
TTL
output
None
15ms
Zero
Zero
30mA*
-
Option R
Option RS
4
4
20ms
20ms
150V
200V
125V
130V
30W/60VA
200mA
<1 Ohm
10 Ohms
Open circuit 1012 Ohms
±1 digit
Programmable
Option FR
Option FRS
2
2
5ms
5ms
150V
200V
125V
130V
30W/60VA
200mA
<1 Ohm
10 Ohms
Open circuit 1012 Ohms
±0.1% F.S. typical
±0.1% F.S. typical, fixed**
*
The total source/sink current for the TTL outputs must not exceed 50mA.
**
Ensure optimum gain range is selected in order to minimise the effects of this
(analogue) hysteresis on the overall accuracy of Options FR/FRS.
38
9.3
Programming Limits
In order for the limits to function, it is necessary to programme the limit values and some
other factors associated with their operation.
Please read Sections 6.1, 6.2, 6.3, & 6.4. This will give essential information on accessing
the menu, entering numbers and selecting items from the programming menus. The Menu
Map (Section 6.10) may also be useful. Once you have read Sections 6.1 to 6.4, return to
this section.
When the Limits menu is accessed, the display reads [l 1-4], denoting Limits 1 to 4. This
will read [l 1-2] if you have option FR or FRS fitted as there are 2 limits available with the
fast limit option.
Press ENTER.
Press the UP ARROW or DOWN arrow until the display shows the limit you wish to
change. For example [l 2]. Press ENTER to select your chosen item.
Again using the UP ARROW and DOWN ARROW keys, choose the operation mode of the
limit. The choices and their description are as follows:
[OFF]
[HI]
[LO]
[d.tion]
OFF. The limit is turned OFF which is the DEFAULT CONDITION. Selecting
OFF exits the set up of the current limit. If the current limit is the last limit (L2
for option FR and FRS, L4 for all other cases), the unit will exit the limits
menu.
HIGH. The limit activates when the input signal is higher than the set point.
LOW. The limit activates when the input signal is lower than the set point.
DEVIATION. The limit activates when the input signal deviated from the set
point by more than a specified amount. For example, a set point of 100 with
a deviation of 10 would be activated below 90 and above 110.
Deviation is not available with Options FR/FRS.
Press ENTER to make your selection.
The display will briefly show [Funct].
Using the UP ARROW and DOWN ARROW keys, view the six LIMIT INPUTS available to
be monitired. For most applications the [n-IP] will be appropriate. Full details are as
follows:
[n-IP]
[G-IP]
[t-IP]
[n-IP]
[n-IP]
[n-IP]
NET INPUT is the value seen on the display of the unit in normal operational
mode.
GROSS INPUT disregards any zero offsets introduced (eg by pressing the
ZERO key) since calibration.
TARE INPUT is the zero offset introduced by the ZERO function.
WITH MAX INDICATOR. MAX INPUT is monitored.
Section 10 gives
WITH MIN INDICATOR.
MIN INPUT is monitored..
further details.
WITH TIR INDICATOR.
TIR INPUT is monitored.
Press ENTER to make your selection.
39
Number entry, quick refresher!
Increment/decrement a digit using the UP ARROW or DOWN ARROW key.
Step digits using the ENTER key
Enter the value using the ENTER and SETUP keys together or if the left-hand digit is
flashing, by pressing ENTER.
In order to correct an error, press RESET to return to the original value.
Negative numbers are entered using the left-hand digit.
The display will briefly show [SetPt] (SET POINT) and then show a number. Enter the
required value of the set point. It can be any value between minus 99999 and plus 99999.
Section 6.3 deals with number entry if you're not sure.
If you have selected [d.tion] (DEVIATION) as the operation mode, the unit will at this point
request the level of deviation allowed. ([d.tion] will appear on the display briefly). Input this
value. THIS STEP WILL BE OMITTED IF THE OPERATION MODE IS NOT [d.tion].
Next the unit will momentarily display [HYS] (HYSTERESIS). Hysteresis provides a dead
band around the limit value. If for example, the signal from the sensor has a lot of
fluctuation, as the average signal approaches the set point, the limit will be rapidly
triggered on and off. The hysteresis value allows a dead band to be configured. If for
example the limit is a high limit with a set point of 100 and hysteresis of 10, the limit will
trigger at 100 but not go off until 90.
Hysteresis is not programmable with Options FR/FRS.
Finally, the display will show [Lat.N] (LATCHING NO). This sets the limits to be nonlatching. If this is set to [Lat.Y] (LATCHING YES) using the UP ARROW key, once the limit
is triggered, it will stay triggered even if the signal falls below the set point. The limit must
be reset before it will go off. See Section 4 for details of how latched limits are reset. Press
ENTER once the required selection is made.
Note: latching LOW limits are inoperable.
The display will now prompt entry of the next limit unless this was the last limit (L4 for R
and RS, and L2 for FR and FRS). If it was the last limit, the display will show RUN. Press
enter (and wait for 2 seconds). The unit has now left set-up mode and is in normal
operating mode.
To make a quick exit from the limits menu, whilst the display is showing [L1], [L2, L3] or
{L4] press RESET. The display will then show [run]. Press ENTER and after a 2 second
delay, the unit will return to normal operating mode.
40
10
MAX /MIN (PEAK CATCHER)
10.1
How to Identify if Your E725 Has an Option FM Card Fitted
Please compare the part number of your E725 (located on a label on top of the housing)
with the following:
E725-NNN-NNN-XXX-N-N where XXX is important and NNN is not important here.
If XXX = FM, then the unit has option FM (also referred to as fast MAX/MIN or Peak
catcher) fitted.
Any other value of XXX is not relevant to this section and indicates that the E725 does not
have option FM. However, the standard MAX/MIN features are still available.
10.2
MAX/MIN Description (E725 Without Option FM)
The standard E725 monitors the transducer signal and stores the maximum (MAX),
minimum (MIN), and the total indicated range (TIR). The total indicated range is the
difference between the maximum and the minimum.
To the left of the display, the up arrow (triangle) indicates that the display is showing the
MAX value, the down arrow indicates that MIN is being displayed and both together
indicate that the TIR is being displayed. Pressing the MODE key rotates the display
NORMAL to MAX to MIN to TIR to NORMAL etc. An external device may also switch
modes using the digital inputs. Section 4.3 gives further information.
Pressing MODE and RESET together resets the MAX/MIN value.
10.3
MAX/MIN Description (E725 With Option FM)
Please use Section 10.1 to check if your unit has Option FM fitted.
To the left of the display, the up arrow (triangle) indicates that the display is showing the
MAX value, the down arrow indicates that MIN is being displayed and both together
indicate that the TIR is being displayed. Pressing the MODE key rotates the display
NORMAL to MAX to MIN to TIR to NORMAL etc. An external device may also switch
modes using the digital inputs. Section 4.3 gives further information.
The MAX/MIN value is reset by pressing MODE and RESET together or by using the
RESET input on the FM option board connector.
Option FM provides a fast analogue peak catcher which uses analogue comparators to
catch the MAX (peak) and MIN (trough or valley) of the input signal. The peak catcher is
suited to very rapidly changing signals. Please note that the MAX and MIN signals are
stored as analogue values and so may flicker slightly due to electrical interference. Also,
there will be a signal droop that is normally negative-going.
41
In addition to the standard analogue output (see Section 8), there is an analogue output
available from the FM option board connector. The FM analogue output is a non-scaled
version of the stored value. If the coarse gain range is correctly set for the transducer, the
output of the peak for example, should be between 5V and 10V for a peak value equal to
the full-scale range of the transducer.
In order accurately to identify the relationship between the FM analogue output and the
displayed peak value, measure the FM analogue output voltage and then compare it with
the peak value shown on the E725 display.
The TIR (difference between MAX & MIN) has the possibility of being twice the F.S. value
of the transducer. For this reason the analogue output of TIR is halved.
10.4 MAX/MIN Connections and Specification (E725 Without Option FM)
The standard E725 connections for externally changing display mode and resetting MAX /
MIN and TIR are given in section 4.3.
Specification for MAX/MIN (E725 Without Option FM).
Range of capture.
Any value between -99999 and +99999.
Min pulse width for ±1 digit Guideline figures:- 40ms at filter value 1, 100ms at filter
accuracy.
value 5.
10.5
MAX/MIN Connections and Specification (E725 With Option FM)
The FM board can be fully controlled from the front panel. However, if external control is
required or an analogue output of the MAX or MIN value is required, connections can be
made to the card.
The connections are made using the 9 pin D plug (supplied) to the connector marked
OPTION on the rear of the E725. The connections and their descriptions are as follows:PIN
1
2
3
4
5
6
7
8
9
Shield
Function
MAX output
MIN output
TIR output
Analogue common
Reset
+5V
MAX comparator O/P
MIN comparator O/P
Digital common
Cable shield
Description
Voltage between pin 1 and 4 proportional to MAX
Voltage between pin 2 and 4 proportional to MIN
Voltage between pin 3 and 4 proportional to TIR/2
Common for above analogue outputs
Resets stored MAX and MIN when linked to pin 6
5V output for above.
Logic O/P. Goes low when input sig. > current MAX.
Logic O/P. Goes low when input sig. < current MIN.
Common for Pins 7 & 8
Cable Shield.
Option FM can be reset using the connector labelled DIGITAL I/O (see section 4.3) or by
using the pin 5 of connector marked OPTION.
Specification for OPTION FM
Range of capture
Accuracy for 0 to FS step.
Drift (droop)
Any value between -99999 and +99999
Change in 10ms
= 0.1% FS
Change in 1ms
= 0.2% FS
Typically 1 digit per 3 seconds, normally negative going, even if
the signal is negative.
42
Notes
1)
The E725 FM has a very rapid response to transient signals. Ensure that the E725
has adequate supply-noise suppression otherwise erroneous MAX/MIN values may
be stored.
When the MAX/MIN is RESET, there will nearly always be some residual value (i.e. not
exactly zero). This is due to the small amount of noise inherent on the signal. The display
may appear stable due to the digital filtering.
Remember that the FM board is designed to store fast peaks. If there is a fast transient
information on your signal due to mechanical or electrical noise, the FM board will catch it.
The FM board is not able to discriminate between desirable and undesirable MAX or MIN
values.
If you do encounter problems with unexpected peak values, monitor the signal with an
oscilloscope in order to see what is causing them. They are almost always due to noise
induced into cabling from motors, solenoids or other electrically noisy equipment.
If you wish to display or store a fast MAX or MIN value for a long time, use the digital
HOLD function (see Section 4.3 for details)
11
TWO CHANNEL VERSIONS
11.1 Description
There are 3 dual options available and your use of this section will depend on which option
is fitted. Please check the part number located on a label on the top of the housing.
E725-NNN-NNN-XXX-N-N where XXX is important and NNN is not important here.
If XXX = 2DC1, then the unit has two DC1 input boards fitted
If XXX = 2DC2, then the unit has two DC2 input boards fitted
If XXX = 2DC3, then the unit has two DC3 input boards fitted
Any other value of XXX is not relevant to this section.
The dual inputs are of the same type. That is, if the first input is a DC1, the second is also
a DC1. In addition to this, as the two input cards share the gain range, the transducers
must have a similar sensitivity ±15%, and they must display the same full-scale value.
The second channel is connected via a 9 pin D type the OPTION .
When an E725 is fitted with a second input card, four display functions are activated.
To move between functions, press MODE and FUNCTION together. The 4 LEDs marked
F1, F2, F3 and F4 located just above the MODE key indicate the function that is selected.
The functions are as follows:F1
F2
F3
F4
A
B
(A+B)/2
A-B
Transducer A input
Transducer B input
Average of A and B input
Difference between A and B
43
Limit & MAX/MIN monitor selected function.
MAX/MIN and any latched limits are reset
when the function mode is changed.
ZERO FUNCTION. Each of the modes has a separate zero point. Therefore, pressing
ZERO whilst in mode F1 (transducer A) will have no effect on the calculation of A-B (mode
F4) for example. If modes F3 or F4 appear to be incorrect, RESET ZERO on all four
modes to ensure that all modes have the zero offset removed. Calculations should now be
correct.
ANALOGUE OUTPUT. The analogue output is proportional to the currently selected
mode. Mode F4 is halved because when the outputs of A & B are -10V & +10V
respectively, the output would otherwise be (-10)-(+10)= -20V which is not possible. The
output is therefore (A-B)/2.
11.2
Connections for Second DC Input Channel
The connections to the second DC input are IDENTICAL to the first. Refer to section 5 for
transducer connections.
11.3
Calibrating the Second Transducer
This section assumes that the first transducer is calibrated. If not, see Section 7.
Select F2 (Transducer B input). See above for how to do this.
Ensure that zero load/pressure etc. is applied to the transducer and press the ZERO key.
Apply a known load/pressure etc. to the transducer (or operate the CAL function from run
mode) and adjust the input balance potentiometer (just above the power input lead on the
rear panel and labeled 'X') until the required display is obtained. Please note that there is a
15% F.S. adjustment on this potentiometer so if the sensitivity of the transducers differs by
more than this, it will not be possible to match the two channels.
12
RS232/RS485 OUTPUTS
The E725 is fitted with an RS232 output as standard, or an RS485 output as an option.
The last-but-one digit of the part number indicates whether the RS485 option is fitted. If it
is a '0' the output is RS232, if it is a '1' the output is RS485.
The serial outputs enable the user to connect one E725 using RS232, or up to 256 E725
units using RS485, to a computer. This allows the display reading for example to be
directly transferred to a PC.
In addition to this, a PC may take operational control of the unit, enabling actioning of all
front panel (and other) functions.
Calculated channels may be defined, allowing for example the display to read different
engineering units (user selectable) for the same transducer input.
Recognising that only a small number of customers use RS232 and in an attempt to save
paper, there are no further details of the RS232 or RS485 output in this manual.
Please contact RDP or your distributor to order a copy of the full Serial Communications
Manual, part number CD1423.
44
13
SPECIFICATION
The specification for the E725 DC input versions is as follows:Power supply
For supply identification, connections, tolerance and fuse
values see Section 3.1 and 3.3.
Operating temperature.
Ac supply, -10 to +45°C, (14 to 113°F)
Dc supply, -10 to +55°C, (14 to 131°F)
Dimensions
DIN437000. Width 92, height 44, depth 180 (inc. connectors)
Case material
Aluminium anodised black.
Weight
Ac supply. 0.51kg (excluding connectors)
Dc supply. 0.43kg (excluding connectors)
Controls
Indicators.
Display resolution
Display update rate
A to D resolution
Digital inputs
Digital outputs
RS232/485
Connectors
Limits
Transducer input and
excitation
Shunt Resistor Value
Amplifier Input Resistance
Amplifier Linearity
Amplifier CMRR
Amplifier CMVR
Amplifier Temp. Coefficient
Analogue output
Four membrane keys with tactile feedback
Potentiometers for analogue output zero and gain.
5 digits, 13.2mm high.
4 LEDs for limits & 4 LEDs for function
1 in ±99999
3Hz
1 in ±99999
HOLD, ZERO, RESET, opto isolated, 5 to 50V into 2k Ohms or
TTL. (See also section 4.3).
TTL for limits (see Section 9.2)
See section 12.
Transducer 9 pin D type male,
Option
9 pin D type female (male if dual input)
Digital I/O
15 pin D type male
See section 9.2
See section 5.1
59k Ohms (0.1%) fitted as standard by RDP
100M Ohms min
0.02% F.S.
110dB typical. Dc to 50Hz
±12.5V typical
Zero; 0.3µV/°C RTI Typical. Gain; 0.003% F.S./°C Typical
See section 8.2
EMC
The unit passed the following standards.
a)
EN55022.
:
Conducted and radiated emissions.
b)
EN61000-4 -2
:
Electrostatic discharge
-3
:
Radiated immunity
-4
:
Fast transient bursts
-6
:
Conducted immunity
-11
:
Supply voltage dip
Note: Because of the high gains involved when low output transducers are used, spurious
display/analogue outputs may be seen in the presence of strong RF fields at certain
frequencies. These frequencies will depend on:
a)
b)
c)
The cable length, especially the transducer's cable.
Type of cable. (Quality of shield etc.)
Cabling and grounding point Layout.
45
14
GLOSSARY OF TERMS
Analogue output
Bar
Bar g
Bipolar
Bridge shunt
Calculated
channels
Calibration
Calibration factor
Calibration point
Calibration zero
Capacity
Counts
D2-Series
Displacement
Engineering unit
Excitation
(voltage)
Full-scale
Function mode
Half bridge
transducer
Hysteresis
Hysteresis
IP65
Limit
Low pass
LVDT
A continuously variable voltage or current signal proportional to a
measured quantity.
An engineering unit for pressure measurement.
An abbreviation of bar gauge. The addition of the word gauge
states that the measurement is relative to atmospheric pressure
(as is usually the case).
Working in a range from a negative value, through zero, to a
positive value.
Alternative to shunt resistor.
On 2-channel E725's where the channels are labelled A and B, the
Calculated channels are A-B and (A+B)/2.
Setting equipment (e.g. an E725 and a transducer) to give a known
display or output for a particular measured quantity or range of
quantities.
Alternative to full-scale output referred to excitation voltage.
A point chosen for correlation between the physical quantity
applied to a transducer and transducer output, E725 display or
E725 output.
The zero point defined during the main calibration procedure
Alternative to full-scale.
Uncalibrated value displayed by E725.
A series of RDP manufactured LVDTS with integral signal
conditioning providing dc-in/dc-out operation.
General technical word for quantities such as distance, height,
length, diameter etc.,
A unit of measure of a physical quantity (e.g. In the case of
displacement, mm).
The voltage applied to an unamplified (typically strain gauge)
transducer to make it work.
The total specified measurement range of a transducer or
instrument.
In some cases the E725 can display A, B, A-B, (A+B)/2 or
alternative Engineering units (lbs., kg etc.,).These display modes
are called Function modes
A transducer (usually strain gauge or inductive) requiring bridge
completion components to operate with an E725
(In the context of limits) A means of avoiding repeated re-triggering
of a limit when the input signal dwells close to the set point.
(In the context of transducers) An undesirable characteristic, the
difference between the rising signal and the falling signal for the
same physical quantity (similar to backlash in a machine).
A reference to a generally recognised Ingress Protection index.
IP65 defines total protection against dust and low-pressure water
jets from any direction.
A facility to indicate if a signal is above or below a particular level
Term applied to electronic filters, which remove high frequencies
and does not affect low frequencies.
Linear Variable Differential Transformer, a type of transducer
technology, particularly well suited to displacement measurement.
46
Max
Mechanical relay
Min
Normal operating
mode
Opto-isolated
Peak
Polarity
Potentiometer
Potentiometric
transducer
PSI
PSIG
RS232
RS485
Sensitivity
Serial output
Set point
Shunt calibration
Shunt calibration
factor
Shunt calibration
output
Shunt calibration
reading
Shunt resistor
Solid-state relays
Strain gauge
transducer
Supply voltage
TIR
Transducer
Transmitter
Trough
TTL
Unipolar
Valley
The maximum transducer reading stored since last reset.
Electronically operated switch with mechanical parts.
The minimum transducer reading stored since last reset
The status of the E725 on power-up (after a short power-up
sequence) where a calibrated E725 displays a measured quantity.
A means of protecting a digital input via an optical device,
removing conventional electrical continuity.
Alternative for max
Whether a quantity is positive or negative
A variable resistor often used for making adjustments
A transducer employing potentiometric (varying electrical
resistance) technology.
Pounds (per) Square Inch. An engineering unit for pressure
measurement
An abbreviation of psi gauge. The addition etc., (as bar g).
A particular type of serial communication
A particular type of serial communication
The relationship between transducer output, applied physical
quantity and (in some cases excitation voltage)
A means of transferring information or instruction in a digitally
coded form.
The level at which a limit is triggered
A means of calibrating certain strain gauge transducers where a
shunt resistor is used to produce a transducer output without
applying a physical quantity (e.g. pressure) to the transducer
Alternative to shunt calibration output referred to excitation voltage.
The output obtained when a shunt resistor is applied to a strain
gauge transducer.
A reading obtained when a shunt resistor is applied to a strain
gauge transducer.
The resistor used for shunt calibration.
An electronic device with similar features to a mechanical relay, but
with no moving parts.
A transducer employing strain gauge technology
The voltage applied to an amplified transducer to make it work.
Total indicated reading, the difference between max and min
An electronic measuring device which converts a physical quantity
(e.g. pressure) into an electronic signal (e.g. voltage).
A widely used term for an amplified transducer with a 4 to 20mA
Output
Alternative for min
Transistor Transistor Logic, the output of an IC.
Working in a range 0 to a positive value
Alternative for min
47
15
COMMON CONVERSION FACTORS
Pressure
Psi
Bar
in. of H2O at
4°C
in. of Hg
mm. of Hg
(Torr)
Pascals
Psi
1
14.504
3.6127 x 10-2
0.4912
1.934 x 10-2
1.4503 x 10-4
Bar
6.8948 x 10-2
1
2.491 x 10-3
3.3864 x 10-2
1.333 x 10-3
10-5
In. of H2O
at 4°C
27.68
401.48
1
13.60
0.5354
4.014 x 10-3
In. of Hg
2.036
29.53
7.355 x 10-2
1
3.937 x 102
2.953 x 10-4
mm. of Hg
(Torr)
51.715
750.06
1.868
25.4
1
7.502 x 10-3
Pascals
6.8948 x 103
1 x 105
2.491 x 102
3.386 x 103
1.333 x 102
1
Load
Torque
Pound (lb.)
Pound
Kg
Newton
1
2.205
.2248
Kg
0.4536
1
0.102
Newton
4.448
9.807
1
48
1 oz-in
1 lb.-in
1 lb.-ft
1 kg/m
Nm
7.06 x 10-3
0.113
1.3558
9.80665
16
APPENDIX 1 DIMENSIONAL DETAILS
49
17
APPENDIX 2 – COMPLETE CONNECTION LISTING
E725 9-WAY CONNECTIONS (TRANSDUCERS AND OPTIONS)
AC
DC TRANS (ALL
OPT
OPT
OPT
PIN
OPT R
TRANSDUCER VERSIONS)
RS
FR
FRS
RL1
1
Exc. High
Excitation +
RL1
RL1 N.O. RL1
N.O./N.C
2
Exc. Low (0V) Excitation RL1 Com RL1
RL1 Com RL1
RL2
3
Signal Low*
Signal +
RL2
RL1 N.C. No Con
N.O./N.C.
4
Signal Hi*
Signal -
5
0V (Ground)
0V (Ground)
6
M/S
Sh.Cal.1
RL2 Com
RL2
RL3
RL3
N.O./N.C.
RL3 Com RL3
OPT
FM
Max
Out
Min Out
TIR Out
RL2 N.O. RL2
AN.Co
m (0V)
RL2 Com RL2
Reset
RL2 N.C. No Con 5V Out
Max
RL4
L1
7
½ BR.R Hi
+15V Out
RL4
L1 Logic
CMP
N.O./N.C.
Logic
Out
Min
-15/-8/-6V Out
L2
8
½ BR.Com
RL4 Com RL4
L2 Logic
CMP
(DC1/DC2/DC3)
Logic
Out
Logic
Logic
Dig.Co
9
½ BR.R Low
Sh.Cal.2
No Con
No Con
Com
Com
m (0V)
* Reverse for 2AC Option
Transducer connectors are sockets
Options are plugs except 2AC/DC
15-WAY CONNECTIONS (DIGITAL I/O)
PIN DIGITAL I/O
PIN
INPUTS
1
Rs232 rx
9
Reset/Mode
2
Rs232 tx
10
Reset/Zero
3
Rs232 Com.(Ground)
11
Reset/Limits
4
Limit 1 Out
12
Hold/Reset
5
Limit 2 Out
13
Fast Hold
6
Limit 3 Out
14
Com.
7
Limit 4 Out
15
(+5V Out)
8
Limit Com (Ground)
On 9-15 way connect shields/shields to shells
ANALOGUE JACK
Contact
Output
Inner
4-20mA
Middle
±10V
Outer
0V (Com)
SUPPLY AC/DC
Brown
100-230V ac
Blue
Neutral
Green/Yellow
Ground
Red
V+ DC
Blue
V- DC
Shield
Ground
50
18 WARRANTY AND SERVICE
WARRANTY.
R.D.P. Electronics products are warranted against defects in materials or workmanship.
This warranty applies for one year from the date of delivery. We will repair or replace
products that prove to be defective during the warranty period provided they are returned
to R.D.P. Electronics.
This warranty is in lieu of all other warranties, expressed or implied, including the implied
warranty of fitness for a particular purpose to the original purchaser or to any other person.
R.D.P. Electronics shall not be liable for consequential damages of any kind.
If the instrument is to be returned to R.D.P. Electronics for repair under warranty, it is
essential that the type and serial number be quoted, together with full details of any fault.
SERVICE.
We maintain comprehensive after-sales facilities and the instrument can, if necessary be
returned to our factory for servicing.
Equipment returned to us for servicing, other than under warranty, must be accompanied
by an official order as all repairs and investigations are subject to at least the minimum
charge prevailing at the date of return.
The type and serial number of the instrument should always be quoted, together with full
details of any fault and services required.
IMPORTANT NOTES.
1.
No service work should be undertaken by the customer while the unit is under
warranty except with the authorisation of RDP Electronics.
2.
If the instrument is to be returned to R.D.P. Electronics for repair, (including repair
under warranty) it is essential that it is suitably packed and that carriage is insured
and prepaid. R.D.P. Electronics can accept no liability whatsoever for damage
sustained during transit.
3.
It is regretted that the above warranty only covers repairs carried out at our factory.
Should the instrument have been incorporated into other equipment that requires
our engineers to perform the repair on site, a charge will be made for the engineer's
time to and from the site, plus any expenses incurred.
The aforementioned provisions do not extend the original warranty period of any product
that has been either repaired or replaced by R.D.P. Electronics.
THIS WARRANTY MAY BE NULL AND VOID SHOULD
THE CUSTOMER FAIL TO MEET OUR TERMS OF PAYMENT.
51