
Operating Instructions
Digital Indicator Model A-RB-1

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Contents
Page Section Topic
4 1. General
5 2. Layout of front panel
5 2.1 LED display 'A'
5 2.2 MODE key 'H'
5 2.2.1 Real mode 'h'
5 2.2.2 HOLD mode 'h'
6 2.2.3 MIN mode (minimum memory) 'h'
6 2.2.4 MAX mode (maximum memory) 'h'
6 2.3 Set key descending value ( ) 'B'
6 2.4 Set key ascending value ( ) 'C'
6 2.5 Programming key PROG 'F'
(see also appendix A)
7 2.5.1 Programming the indication
Low end of scale
High end of scale
Decimal point
Input signal
Output signal
Damping
Reference for damping
Baud rate setting
10 2.5.2 Verification of programmed settings
10 2.5.3 Compensation of zero offset
11 2.6 Model A-RB-1-D with 2 alarms
(see also appendix B)
11 2.6.1 Setting of alarm 1
14 2.6.2 Setting of alarm 2
14 2.6.3 Verification of set points of alarm 1
14 2.6.4 Verification of set points of alarm 2
14 2.7 Reset key 'G'
14 2.7.1 Erase data memory
15 2.7.2 Exit programming mode
15 2.7.3 Exit verification mode

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Contents
Page Section Topic
15 3. Layout of back panel terminals
16 3.1 Layout of 15-pin plug 'J'
16 3.1.1 Opening the case
17 3.1.2 Scheme of line power settings
17 3.2 Layout of 9-pin plug 'K'
18 3.3 Wiring examples
19 3.4 Layout of 9-pin Sub-D plug 'L'
19 4. Option serial interface RS-232
20 4.1 Transfer of data and parameters
22 4.2 Programming of parameters
23 5. Error messages
24 5.1 Error messages E1/-E1
24 5.2 Error messages E2/-E2
24 5.3 Error messages E3/-E3
24 5.3.1 Error message E3
25 5.3.2 Error message -E3
26 6. Preparing for installation
26 7. Environment
26 8. Setting of physical unit
26 9. Maintenance
27 10. Specifications
28 App. A Schematic description of settings and data
transmission
32 App. B Schematic description of alarm settings
and verifications
34 App. C Dimensions
36 App. D Layout of front and back panel

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Safety Instructions
Preface
Many thanks for buying our digital indicator Model A-RB-1.
This operating manual includes instructions for the operation of the
digital indicator and information on its functionality. Read these operating instructions thoroughly prior to starting up the digital indicator. In
order to avoid any damage or injuries that might be caused by any nonobservance of the appropriate regulations, please ensure that the person
operating this digital indicator receives these operating instructions.
The appropriate national safety regulations (e.g. VDE 0100) must be
observed when mounting, starting up and operating these displays.
Serious injuries and/or damage can occur should the appropriate
regulations not be observed. Only appropriately qualified persons should
work on these instruments.
1. General
The digital indicators A-RB-1 are precision instruments for the measurement of current and voltage signals of pressure or other transmitters.
The instruments are normally DIN-Size panel mounting (96 x 48 x 190
mm) per IEC 61 554.
Indication is made via a 3 1/2 -digit LED display, covering a range from
-1999 to +1999 digits. The actual span to be indicated can be easily
programmed anywhere within this range. The same applies to decimal
point, signal input, analogue output damping and baud rate of the data
interface. All programming can be made while the instrument is
operative.
This versatility is achieved by means of a powerful microprocessor,
which also controls all other functions.
An inbuilt isolated transformer provides power supply of DC 24 V max.
30 mA to energise transmitters connected.
Analogue output of 0 … 10 V, 0 … 20 or 4 … 20 mA, adjustable
damping, as well as HOLD memory and MIN and MAX memory are serial
standard.

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Optionally available are 2 alarm contacts and also a serial RS-232
interface.
2. Layout of front panel
The position of the operation and connection elements is shown in
appendix C.
2.1 LED display 'A'
By means of the MODE key (see section 2.2), the display can be set to
optionally read the REAL value measured, or either one of the values
stored in the HOLD, MIN or MAX memory.
2.2 MODE key 'H'
The MODE key is found at the right-hand side next to the display,
indicated by REAL, HOLD, MIN and MAX. Hitting changes the modes in
consecutive order. A red LED indicates the active mode.
2.2.1 REAL mode 'h'
Indicates the current value measured.
2.2.2 HOLD mode 'h'
Hold the value indicated at the very moment the key is pressed.
Measurement continues in the background, meaning that the memories
of Minimum and Maximum as well as the alarm contacts continue to
operate. HOLD discontinues upon further hitting of the MODE key or
hitting of the RESET key (see 2.7).

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2.2.3 MIN mode (minimum memory) 'h'
The lowest value indicated since last hitting of the RESET key is
memorised and will be displayed in this mode. Measurement continues
in the background, meaning that the memories of MIN and MAX as well
as the alarm contacts continue to operate. MIN discontinues upon
further hitting of the MODE key. Hitting of the RESET key erases the
memory (see 2.7).
2.2.4 MAX mode (maximum memory) 'h'
The highest value indicated since last hitting of the RESET key is
memorised and will be displayed in this mode. Measurement continues
in the background, meaning, that the memories of MIN and MAX as well
as the alarm contacts continue to operate. MAX discontinues upon
further hitting of the MODE key. Hitting of the RESET key erases the
memory (see 2.7).
2.3 Set key descending value ( ) 'B'
Selects the next lower value or individual parameter during programming.
2.4 Set key ascending value ( ) 'C'
Selects the next higher value or individual parameter during programming.
2.5 Programming key PROG 'F'
Hitting of this key actuates the programming mode, at which all
operative parameters can be set and verified.
2.5.1 Programming the indication (see also appendix A)
All programming is made in consecutive order by initially holding the
PROG key pressed for approx. 5 seconds, until the message SCL (for
scaling) appears instead of PRO for programming.

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Press PROG once more: -A-appears, standing for "Low end of scale".
Press PROG once more: The "MIN" LED flashes and the corresponding
value is displayed. Change this value as desired by hitting the (
) and
(
) keys. Press PROG once more: The new value will be memorised.
This is indicated by 3 dashes "---" appearing for a few seconds.
The "MIN" LED extinguishes and -E-appears, standing for "High end of
scale". Press PROG once more: The "MAX" LED flashes and the
corresponding value is displayed. Change this value as desired by
hitting the (
) and ( ) keys. Press PROG once more: The new value
will be memorised. This is indicated by 3 dashes "---" appearing for a
few seconds.
The "MAX" LED extinguishes and dP appears, standing for "Decimal
point". Change the decimal point as desired by hitting the (
) and ( )
keys. Press PROG once more: The new position of the decimal point will
be memorised. This is indicated by 3 dashes "---" appearing for a few
seconds after which InX appears, standing for "Signal input X", where
"X" stands for figures 1 to 3 as explained below.
Change this value as desired by hitting the (
) and ( ) keys.
X = 1: In1 = Input signal voltage 0 ... 10 V
X = 2: In2 = Input signal current 0 ... 20 mA
X = 3: In3 = Input signal current 4 ... 20 mA
Press PROG once more: The new value will be memorised.

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This is indicated by 3 dashes "---" appearing for a few seconds after
which OuX appears, standing for "Output signal X", where "X" stands for
figures 1 to 3 as explained below. Change this value as desired by hitting
the (
) and ( ) keys.
X = 1: Ou1 = Output signal voltage 0 ... 10 V
X = 2: Ou2 = Output signal current 0 ... 20 mA
X = 3: Ou3 = Output signal current 4 ... 20 mA
Press PROG once more: The new value will be memorised .This is
indicated by 3 dashes "---" appearing for a few seconds.
Subsequently "-d- (damping)" appears automatically. After hitting the
key once more the current setting of the damping is displayed. The
damping can be set within a range of 0.1 s ... 50.0 s. The damping can
be changed in 0.1 s steps using the (
) and ( ) keys.
The damping is adapted from the behaviour of a capacitor. After the set
time (=t) has passed, approx. 63% of the changed value is applied. After
5 x t has passed, approx. 97% of the changed value is applied.
Press PROG once more: The new damping value will be memorised.
This is indicated by 3 dashes "---" appearing for a few seconds.
Then dXX (reference of damping) is displayed. XX stands for the selected
setting. The damping can be activated for the display, the analogue
output signal, the alarm contacts and the MIN / MAX memory in any
combination as specified in the following table:

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Setting Display Analogue Alarm MIN / MAX
d XX output contacts memory
d011000
d020100
d031100
d040010
d051010
d060110
d071110
d080001
d091001
d100101
d111101
d120011
d131011
d140111
d151111
(0: Damping deactivated, 1: Damping activated)
The value for dXX can be changed using the (
) and ( ) keys. Press
PROG once more: The new value will be memorised. This is indicated by
3 dashes "---" appearing for a few seconds.
With instruments not featuring the serial data interface, programming is
now complete and standard operating mode will be automatically
selected.
With instruments featuring the serial data interface, -b- appears. After
hitting the key once more the current setting of the Baud rate of the
serial interface (RS 232) is indicated. Change this value as desired by
hitting the (
) and ( ) keys.
Display Baud rate
01.2 1200 Baud
02.4 2400 Baud
04.8 4800 Baud
09.6 9600 Baud
19.2 19200 Baud
38.4 38400 Baud

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Press PROG once more: The new value will be memorised. This is
indicated by 3 dashes "---" appearing for a few seconds. Programming
is now complete and standard operating mode will be automatically
selected.
Programming can be terminated at any time by hitting the RESET key. In
this instance, only such changes are accepted that have been acknowledged by appearance of "---". Otherwise, previously set values remain in
effect.
2.5.2 Verification of programmed settings
(see also appendix A)
Short hitting of the PROG key initiates "Pro" to appear at the display,
followed by all current settings in consecutive order, where:
-A- Low end of scale
-E- High end of scale
dP Decimal point
InX Input signal
OuX Output signal
-d- Damping
dxx Reference of damping
-b- At digital interface: baud rate setting
Indication can be terminated at any time by hitting the RESET key. (see
also 2.7)
2.5.3 Compensation of zero offset
Despite careful calibration, the instrument may indicate a zero offset in
operation. This may be caused by a static head acting on the transmitter
or other process conditions. Preferably this should be compensated by
shifting the zero signal of the transmitter. If this cannot be accomplished,
true indication can be achieved by means of shifting low end and high
end indication correspondingly as per examples below.

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Example 1:
Scaling: 0 … 400 bar
Zero offset: 4 bar
Corrective: -4 … 396 bar
Example 2:
Scaling: 0 … 400 bar
Zero offset: -7 bar
Corrective: 7 … 407 bar
However, it is more favourable to compensate the offset by
adjustment the connected transmitter.
2.6 Model A-RB-1-D with 2 alarms
(see also appendix B)
The keys SET 1 (alarm 1) and SET 2 (alarm 2) actuate the programming
mode to enter and verify the settings of the alarms. The max. loading
capacity of the alarms is AC 250 V / 8 A.
2.6.1 Setting of alarm 1
(see also appendix B)
Programming of alarm 1 is made by initially holding the SET 1 key
pressed until SP1 (Set point 1) disappears and the message SE (Set
point makE) appears.
Press SET 1 once more: The red LED in the upper left hand corner of the
SET 1 key flashes and the corresponding value is displayed. Change this
value as desired by hitting the (
) and ( ) keys.
Press SET 1 once more: The new value will be memorised. This is
indicated by 3 dashes "---" appearing for a few seconds.
The LED extinguishes and SA appears, standing for "Set point breAk".
Press SET 1 once more: The red LED in the upper right corner of the
SET 1 key flashes and the corresponding value is displayed. Change this
value as desired by hitting the (
) and ( ) keys.

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Press SET 1 once more: The new value will be memorised. This is
indicated by 3 dashes "---" appearing for a few seconds and the LED
extinguishes.
Contact function can be selected to HIGH ALARM (meaning make on
rising value), or LOW ALARM (meaning make on falling value). This is
easily achieved by programming the make (SE) value either above or
below the corresponding break (SA) value.
Setting (SE) above (SA) means HIGH ALARM. (SE) will energise the alarm
circuit, which will remain energised until the display figure decreases to
reach the value of (SA).
Setting (SE) below (SA) means LOW ALARM. (SE) will energise the alarm
circuit, which will remain energised until the display figure increases to
reach the value of (SA).
The difference between (SE) and (SA) represents the hysteresis across
make and break points of the contact. (This must not be confused with
any hysteresis across approach of the set points with rising and falling
values. This sort of mechanical delay is not apparent with a digital
instrument).
Both values can be programmed without limitations, as the case
demands. Setting both, (SE) and (SA) at the same values, will automatically create HIGH ALARM function.
The LED's in the upper corners of the SET keys are intended to indicate
the alarm configuration together with the relay status. The left LED, when
lit, indicates energised alarm circuit at HIGH ALARM programmed. The
right LED, when lit, indicates energised alarm circuit at LOW ALARM
programmed.
SET 1 key corresponds to alarm 1, SET 2 key corresponds to alarm 2.
Programming of alarm contacts can be terminated at any time by hitting
the RESET key. In this instance, only such changes are accepted that
have been acknowledged by appearance of "---". Otherwise, previously
set values remain in effect.