FISCHER PRO-LINE DE90 User manual

II 3G Ex nA IIC T4 Gc
II 3D Ex tc IIIB T125°C Dc
Operating manual
DE90
Differential pressure transmitter
PRO-LINE ®
09015203 • BA_EN_DE90 • Rev. ST4-D • 11/19 *09015203*

| Masthead FISCHER Mess- und Regeltechnik GmbH
2 BA_EN_DE90
Masthead
Manufacturer: FISCHER Mess- und Regeltechnik GmbH
Bielefelderstr. 37a
D-32107 Bad Salzuflen
Telephone: [phone]
Telefax: [phone]
eMail: [email protected]
web: www.fischermesstechnik.de
Technical editorial team: Documentation representative: T. Malischewski
Technical editor: R. Kleemann
All rights, also those to the translation, reserved. No part of this document may
be reproduced or processed, duplicated or distributed using electronic systems
or any other form (print, photocopy, microfilm or another process) without the
written consent of the company FISCHER Mess- und Regeltechnik GmbH, Bad
Salzuflen.
Reproduction for internal use is expressly allowed.
Brand names and procedures are used for information purposes only and do
not take the respective patent situation into account. Great care was taken
when compiling the texts and illustrations; Nevertheless, errors cannot be ruled
out. The company FISCHER Mess- und Regeltechnik GmbH will not accept any
legal responsibility or liability for this.
Subject to technical amendments.
© FISCHER Mess- und Regeltechnik 2019
Version history
Rev. ST4-A 02/19 Version 1 (first edition)
Rev. ST4-B 10/19 Version 2 (Change technical data, firmware 1.1)
Rev. ST4-C 11/19 Version 3 (corrections)
Rev. ST4-D 11/19 Version 4 (corrections) Measuring range, Accessories

FISCHER Mess- und Regeltechnik GmbH Table of Content
BA_EN_DE90 iii
Table of Content
1 Safety instructions .......................................................................................................... 6
1.1 General................................................................................................................................... 6
1.2 Personnel Qualification........................................................................................................... 6
1.3 Risks due to Non-Observance of Safety Instructions............................................................. 6
1.4 Safety Instructions for the Operating Company and the Operator ......................................... 6
1.5 Unauthorised Modification...................................................................................................... 7
1.6 Inadmissible Modes of Operation........................................................................................... 7
1.7 Safe working practices for maintenance and installation work............................................... 7
1.8 Pictogram explanation............................................................................................................ 7
2 Product and functional description ............................................................................... 9
2.1 Delivery scope........................................................................................................................ 9
2.2 Intended use........................................................................................................................... 9
2.2.1 Explosion hazard area classification.......................................................................................... 9
2.2.1.1 Gas explosion protection ............................................................................................................ 9
2.2.1.2 Dust explosion protection ........................................................................................................... 9
2.3 Function diagram.................................................................................................................... 10
2.4 Design and mode of operation ............................................................................................... 10
2.5 Equipment versions................................................................................................................ 11
2.5.1 Type plate .................................................................................................................................. 12
3 Assembly.......................................................................................................................... 13
3.1 General................................................................................................................................... 13
3.2 Mounting in explosive areas ................................................................................................... 13
3.3 Process connection ................................................................................................................ 13
3.3.1 Replacement plates ................................................................................................................... 14
3.3.2 Cutting ring screw connections .................................................................................................. 15
3.4 Electrical connections............................................................................................................. 15
3.4.1 Operation in areas at risk of explosion....................................................................................... 15
3.4.2 Devices with switch outputs ....................................................................................................... 16
3.4.2.1 3-conductor circuit ...................................................................................................................... 16
3.4.2.2 M12 connector 1: auxiliary energy and analogue output............................................................ 17
3.4.2.3 M12 connector 2: switch outputs ................................................................................................ 17
3.4.3 Device with Modbus................................................................................................................... 18
3.4.3.1 Connection to an existing Modbus RTU network ....................................................................... 18
3.4.3.2 Auxiliary energy supply............................................................................................................... 19
3.4.3.3 M12 plug 1: Modbus IN .............................................................................................................. 19
3.4.3.4 M12 plug 2: Modbus OUT .......................................................................................................... 20
3.4.4 USB port .................................................................................................................................... 20
4 Start-up ............................................................................................................................. 21
4.1 Installation control................................................................................................................... 21
4.2 Switch on the measuring device............................................................................................. 21
4.2.1 Measured value display ............................................................................................................. 22
4.2.1.1 1 channel version ....................................................................................................................... 22
4.2.1.2 2 channel version ....................................................................................................................... 22
4.2.1.3 3 channel version ....................................................................................................................... 23
4.2.1.4 Back lighting ............................................................................................................................... 23
4.2.2 Keyboard.................................................................................................................................... 24

Table of Content FISCHER Mess- und Regeltechnik GmbH
iv BA_EN_DE90
4.3 Setup ...................................................................................................................................... 25
4.3.1 Set menu language.................................................................................................................... 25
4.3.2 Measuring point designation ...................................................................................................... 25
4.3.3 Configuration.............................................................................................................................. 25
4.4 Modbus RTU interface............................................................................................................ 25
5 Operation.......................................................................................................................... 26
5.1 First steps ............................................................................................................................... 26
5.1.1 Operating modes ....................................................................................................................... 26
5.1.2 Menu tree................................................................................................................................... 26
5.1.3 Navigation in the menu tree ....................................................................................................... 29
5.1.4 Directory details ......................................................................................................................... 31
5.1.5 Input ........................................................................................................................................... 31
5.1.5.1 Text input.................................................................................................................................... 31
5.1.5.2 Value input.................................................................................................................................. 32
5.1.5.3 Selection of options .................................................................................................................... 34
5.2 Main menu.............................................................................................................................. 35
5.3 Login....................................................................................................................................... 36
5.3.1 Log in / log out ........................................................................................................................... 37
5.3.2 Timeout ...................................................................................................................................... 38
5.3.3 Manage users ............................................................................................................................ 38
5.3.3.1 User 1 ......................................................................................................................................... 39
5.3.3.2 Administrator .............................................................................................................................. 40
5.3.4 Reset passwords ....................................................................................................................... 41
5.4 Quick access .......................................................................................................................... 41
5.5 Configuration .......................................................................................................................... 43
5.5.1 Channel 1................................................................................................................................... 45
5.5.1.1 Mode C1 ..................................................................................................................................... 46
5.5.1.2 Measurement C1 ........................................................................................................................ 47
5.5.1.3 Characteristic curve C1 (menu expansion) ................................................................................ 54
5.5.1.4 Number format C1 ...................................................................................................................... 61
5.5.1.5 Colour change C1....................................................................................................................... 62
5.5.2 Channel 2................................................................................................................................... 67
5.5.3 Channel 3................................................................................................................................... 68
5.5.3.1 Mode C3 ..................................................................................................................................... 69
5.5.3.2 Measurement C3 ........................................................................................................................ 69
5.5.3.3 Characteristic C3 (menu expansion) .......................................................................................... 70
5.5.3.4 Number format C3 ...................................................................................................................... 77
5.5.3.5 Colour change C3....................................................................................................................... 77
5.5.4 Analog output............................................................................................................................. 78
5.5.4.1 Analog output 1 type................................................................................................................... 79
5.5.4.2 Analog output 1 assignment ....................................................................................................... 79
5.5.4.3 Signal limits ................................................................................................................................ 80
5.5.5 Switch output ............................................................................................................................. 81
5.5.5.1 SP1 assignment ......................................................................................................................... 81
5.5.5.2 SP1 function ............................................................................................................................... 82
5.5.5.3 Switching function....................................................................................................................... 82
5.5.6 Display ....................................................................................................................................... 84
5.5.6.1 Language.................................................................................................................................... 85
5.5.6.2 Designation................................................................................................................................. 85
5.5.6.3 Measuring data display............................................................................................................... 85
5.5.6.4 Colour change assignment......................................................................................................... 86
5.5.6.5 LCD colour.................................................................................................................................. 87
5.5.6.6 LCD lighting ................................................................................................................................ 87

FISCHER Mess- und Regeltechnik GmbH Table of Content
BA_EN_DE90 v
5.5.6.7 LCD contrast............................................................................................................................... 88
5.5.7 Modbus RTU.............................................................................................................................. 89
5.5.7.1 Baud rate .................................................................................................................................... 90
5.5.7.2 Data format................................................................................................................................. 90
5.5.7.3 Modbus address ......................................................................................................................... 91
5.5.7.4 Byte order ................................................................................................................................... 91
5.6 Info.......................................................................................................................................... 92
5.7 Service.................................................................................................................................... 93
6 Servicing........................................................................................................................... 94
6.1 Maintenance ........................................................................................................................... 94
6.2 Transport ................................................................................................................................ 94
6.3 Service.................................................................................................................................... 94
6.4 Disposal.................................................................................................................................. 94
7 Technical data.................................................................................................................. 95
7.1 General................................................................................................................................... 95
7.2 Input variables ........................................................................................................................ 95
7.3 Output sizes............................................................................................................................ 96
7.4 Measuring accuracy ............................................................................................................... 97
7.5 Digital interfaces ..................................................................................................................... 98
7.6 Auxiliary energy ...................................................................................................................... 98
7.7 Operating conditions............................................................................................................... 98
7.8 Display.................................................................................................................................... 98
7.9 Construction design................................................................................................................ 99
7.9.1 Materials .................................................................................................................................... 99
7.9.2 Dimensional drawings................................................................................................................ 99
8 Order codes......................................................................................................................101
8.1 Accessories ............................................................................................................................105
9 Attachments .....................................................................................................................107
9.1 EU Declaration of Conformity .................................................................................................107

1 | Safety instructions FISCHER Mess- und Regeltechnik GmbH
6 BA_EN_DE90
1 Safety instructions
1.1 General
This operating manual is an integral part of the product and therefore needs to
be kept close to the instrument in a place that is accessible at all times to the re-
sponsible personnel.
The following sections, in particular instructions about the assembly, commis-
sioning and maintenance, contain important information, non-observance of
which could pose a threat to humans, animals, the environment and property.
The instrument described in these operating instructions is designed and manu-
factured in line with the state of the art and good engineering practice.
1.2 Personnel Qualification
The instrument may only be installed and commissioned by specialized person-
nel familiar with the installation, commissioning and operation of this product.
Specialized personnel are persons who can assess the work they have been
assigned and recognize potential dangers by virtue of their specialized training,
their skills and experience and their knowledge of the pertinent standards.
For explosion-proof models the specialized personnel must have received spe-
cial training or instruction or be authorized to work with explosion-proof instru-
ments in explosion hazard areas.
1.3 Risks due to Non-Observance of Safety Instructions
Non-observance of these safety instructions, the intended use of the device or
the limit values given in the technical specifications can be hazardous or cause
harm to persons, the environment or the plant itself.
The supplier of the equipment will not be liable for damage claims if this should
happen.
1.4 Safety Instructions for the Operating Company and the
Operator
The safety instructions governing correct operation of theinstrument must be
observed. The operating company must make them available to the installation,
maintenance, inspection and operating personnel.
Dangers arising from electrical components, energy discharged by the medium,
escaping medium and incorrect installation of the device must be eliminated.
See the information in the applicable national and international regulations.
Please observe the information about certification and approvals in the Tech-
nical Data section.
Devices in an explosion-protection version
The instrument must be decommissioned and secured against inadvertent re-
operationif a situation arises in which it must be assumed that safe operation is
no longer possible. Reasons for this assumption could be:
• evident damage to the instrument
• failure of the electrical circuits
• longer storage outside the approved temperature range.
• considerable strain due to transport
Repairs may be carried out by the manufacturer only.
A professional single conformity inspection as per DIN EN 61010, section 1,
must be carried out before the instrument can be re-commissioned. This inspec-
tion must be performed at the manufacturer's location. Correct transport and
storage of the instrument are required.

FISCHER Mess- und Regeltechnik GmbH Safety instructions | 1
BA_EN_DE90 7
1.5 Unauthorised Modification
Modifications of or other technical alterations to the instrument by the customer
are not permitted. This also applies to replacement parts. Only the manufacturer
is authorised to make any modifications or changes.
1.6 Inadmissible Modes of Operation
The operational safety of this instrument can only be guaranteed if it is used as
intended. The instrument model must be suitable for the medium used in the
system. The limit values given in the technical data may not be exceeded.
The manufacturer is not liable for damage resulting from improper or incorrect
use.
1.7 Safe working practices for maintenance and installation work
The safety instructions given in this operating manual, any nationally applicable
regulations on accident prevention and any of the operating company's internal
work, operating and safety guidelines must be observed.
The operating company is responsible for ensuring that all required mainten-
ance, inspection and installation work is carried out by qualified specialized per-
sonnel.
1.8 Pictogram explanation
DANGER
Type and source of danger
This indicates a direct dangerous situation that could lead to death or serious
injury (highest danger level).
1. Avoid danger by observing the valid safety regulations.
WARNING
Type and source of danger
This indicates a potentially dangerous situation that could lead to death or ser-
ious injury (medium danger level).
1. Avoid danger by observing the valid safety regulations.
CAUTION
Type and source of danger
This indicates a potentially dangerous situation that could lead to slight or seri-
ous injury, damage or environmental pollution (low danger level).
1. Avoid danger by observing the valid safety regulations.
NOTICE
Note / advice
This indicates useful information of advice for efficient and smooth operation.

1 | Safety instructions FISCHER Mess- und Regeltechnik GmbH
8 BA_EN_DE90
Other symbols
This table explains how the different objects (menu, parameters, etc.) are
shown in these operating instructions.
Symbol Description
1
This symbol indicates that the switch output con-
tact is open.
1
This symbol indicates that the switch output con-
tact is closed.
Meas.data display This presentation is selected for parameter or
menu names.
U
This symbol indicates that the administrator is still
logged in.
U
1
U
2
U
3
This symbol indicates that one of the users is still
logged in. The number corresponds to the number
of the user.
M
U
1
This symbol indicates that user 1 only has one set
of read rights. The respective user number (see
above) is used for another user.
There is no symbol for writing/read rights.
A
This symbol indicates that there is a submenu
L
This symbol indicates that there is a blocked sub-
menu or parameter.
-E
This symbol is an indicator for the menu output at
the next highest level.
R
This symbol stands for an option that was not se-
lected in a list.
S
This symbol stands for a selected option from a
list.
h
This symbol stands for an activated property.
g
This symbol stands for a deactivated property.
This symbol stands for a short press of a button
This symbol stands for a permanent push of a but-
ton hereinafter call 'repeat' or 'button repeat'.
The guide stands for a collection of links that indic-
ate the path to certain topics.
Table1: Pictogram explanation

FISCHER Mess- und Regeltechnik GmbH Product and functional description | 2
BA_EN_DE90 9
2 Product and functional description
2.1 Delivery scope
• Differential pressure transmitter DE90 PRO-LINE®
version as stated on the type plate with an integrated assembly rail. Attach-
ment screws are not included in the delivery.
• Operating Manual
2.2 Intended use
The DE90 is a differential pressure transmitter with additional switch outputs. It
is suitable for measuring overpressure, under-pressure and differential pressure
in neutral gaseous media.
The device may only be used for the purpose stipulated by the manufacturer.
The manufacturer will not be liable for damage arising from incorrect or im-
proper use.
2.2.1 Explosion hazard area classification
2.2.1.1 Gas explosion protection
Devices with the order code DE90 ## ## ## # 0 # 000 R #### are suitable as
'Electrical equipment for use in potentially explosive areas', Zone 2 - Gases and
vapours.
Designation as per Directive 2014/34/EU:
II 3G Ex nA IIC T4 Gc
2.2.1.2 Dust explosion protection
Devices with the order code DE90 ## ## ## # 0 # 000 R ####
are suitable as 'Electrical equipment for use in areas with combustible dust',
Zone 22 - dry dusts.
Designation as per Directive 2014/34/EU:
II 3D Ex tc IIIB T125°C Dc
-10°C ≤ T ≤ 60°C
amb

2 | Product and functional description FISCHER Mess- und Regeltechnik GmbH
10 BA_EN_DE90
2.3 Function diagram
Sensor 1
Display
þ û ÿ
Analogue output 1
Switch output 1
Switch output 2
Switch output 3
Switch output 4
Differential pressure
Power supply
24 V AC/DC
USB OTG RS485
Modbus
Analogue output 2
Sensor 2
Differential pressure
Channel 1
Channel 2
µC
Fig.1: Function diagram
2.4 Design and mode of operation
The device is based on a piezo-resistive sensor element that is suitable for
measuring overpressure, under-pressure and differential pressure. The pres-
sures to be compared directly act on a silicon diaphragm equipped with a meas-
uring bridge.
When the pressure is equal, the measuring diaphragm is is in its idle state. If a
pressure difference occurs, the diaphragm is deflected, causing a change in
resistance of the applied measuring bridge. This change is evaluated by the
electronics integrated in the instrument and converted into a display, switching
contacts and output signal.
The output signal can be damped, spread, inverted and also non-linearly trans-
formed via a table function.
In the version with only one channel, the device has one analog output and two
switching outputs. In the version with two channels, the device has two analog
outputs and four switching outputs. Analog and switching outputs can be freely
assigned to the measuring channels.
The device can be equipped with two digital interfaces.
1. USB OTG
All devices have a USB interface which can be used for firmware updates
as well as for importing and exporting parameters. This can be done with a
USB stick or by connecting a computer (e.g. laptop).
2. RS485 Modbus RTU
The device can optionally be equipped with a Modbus interface. In this
case, the analog and switching outputs are not available. The measured
values can then be interrogated by the master via Modbus.

FISCHER Mess- und Regeltechnik GmbH Product and functional description | 2
BA_EN_DE90 11
2.5 Equipment versions
Process connections
The presented connections are used for all models.
Model: 1-channel 2-channel
Pneumatics
Plug connection
CK screw connection
Cutting ring connection
+
+
Channel 1 Channel 2
Fig.2: Process connections
Electrical connections
Two M12 flange connectors are used for the electrical connection.
Connector 1
Connector 2
Model: 1-channel 2-channel
Auxiliary energy
Output signal
Switch outputs
Fig.3: Electrical connections
ATEX Version
earth connection conductive housing
Fig.4: ATEX Version

2 | Product and functional description FISCHER Mess- und Regeltechnik GmbH
12 BA_EN_DE90
2.5.1 Type plate
The type plates presented here serve to show an example of the information
shown. Some information may not be required depending on the specific device
model.
1 channel version
1
2
3
4
5
6
7
8
10
12
13
14
9
11
15
2 channel version
15 16
1
2
3
4
5
6
7
8
10
9
11
12
14
13
Fig.5: Type plate
1Conformity 2Device type (order codes)
3Basic measuring range 4Set measuring range
5Durability 6Output signal
7Auxiliary energy 8Production number
9Customer item number 10 ATEX marking
11 Special properties 12 Parameter number
13 Circuit diagram 1 14 Circuit diagram 2
15 Data for channel 1 16 Data for channel 2
Explanations of the symbols
Input
Output
Factory Setting
Production No.
Proof Pressure
Customers Art.no.
Parameter No.
CAL
Pmax
P#
M#
Para. #

FISCHER Mess- und Regeltechnik GmbH Assembly | 3
BA_EN_DE90 13
3 Assembly
3.1 General
The device is designed for installation onto assembly plates or flat walls. To this
end, a pre-mounted 35 mm plastic mounting rail is also supplied. The attach-
ment screws are not included in the delivery.
Alternatively, the device can also be mounted to a 35mm hat rail.
Fixing screw
Ø 3 ...4 mm
35mm top hat rail
mounting rail
1
2
Click
Fig.6: Assembly
At the factory, the device is calibrated for vertical installation, but the installation
position is arbitrary. For any installation positions that are not vertical, the zero-
point signal can be corrected via the installed offset correction.
The enclosure protection type IP 65 is only guaranteed, if a suitable power sup-
ply cable is used (see accessories).
3.2 Mounting in explosive areas
• If operated in explosive areas, the valid local regulations and guidelines for
the installation and operation of electrical systems in explosive areas must
be observed.
• If units are used in potentially explosive areas, the personnel must receive
additional training or briefings or have a permit to work on explosion-protec-
ted units in potentially explosive systems.
DANGER!The operator must ensure that any falling objects cannot collide
with the installed unit.
Steps must be taken to prevent the impact creating sparks so that the protection
class of the casing is no longer guaranteed. This can be avoided by attaching
protective cover, a protective housing or similar.
3.3 Process connection
• By authorized and qualified specialized personnel only.
• The pipes need to be depressurized when the instrument is being connec-
ted.
• Appropriate steps must be taken to protect the device from pressure surges.
• Check that the device is suitable for the medium being measured.
• Maximum pressures must be observed (cf. Tech. data)
The pressure lines must be kept as short as possible and installed without any
tight bends to avoid delays.
The pressure lines must be installed at an inclination so that no water pockets
are created. If the required gradient is not reached, water filters need to be in-
stalled at suitable points.
The process connections are marked with (+) and (-) symbols on the device.
The pressure lines must be mounted according to these symbols.

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
14 BA_EN_DE90
1. Differential pressure measurement
Higher pressure
lower pressure
2. Pressure measurement
Pressure
open
3.3.1 Replacement plates
Depending on the number of measuring channels, the device is equipped with
various replacement plates.
Channel 1 Channel 1 Channel 2
Fig.7: Replacement plate
These replacement plates are equipped ex-works with the required process
connections and the M12 flange connectors for the electrical connection. The
user may not make any independent modifications.
Pneumatic plug connection
for hydraulic hoses
CK quick-action screw connection
for soft hoses
cutting ring screw connection
for hydraulic tubes (stainless steel)
process connection type
Polyamide hose 6 x 4 x 1 mm
size
8 x 6 x 1 mm
PVC hose
TYGON 8 x 6 x 1 mm
6 x 4 x 1 mm
8 mm outside
6 mm outsidetube
®
Fig.8: Process connection table

FISCHER Mess- und Regeltechnik GmbH Assembly | 3
BA_EN_DE90 15
3.3.2 Cutting ring screw connections
wIn the case of cutting ring screw connections, incorrect installation of the
pressure lines can lead to a destruction of the replacement plate due to the
acting forces.
wThe cutting ring screw connection may not be mounted to the device in one
work step.
1. Mount the cutting ring using a pre-assembly connecting piece.
2. Always use a conventional assembly paste (1) to avoid cold welding of the
stainless steel parts.
3. Carry out the final assembly work on the device with just one counter-hold.
Mount the cutting ring screw connection with a quarter or half-turn of the
union nut.
Counter-hold
Connecting piece
Cutting ring
Union nut
Seamless tube 14 6 mm tube
17 8 mm tube
14
Fig.9: Counter-hold for cutting ring screw connections
3.4 Electrical connections
• By authorized and qualified specialized personnel only.
• When connecting the unit, the national and international electro-technical
regulations must be observed.
• Disconnect the system from the mains, before electrically connecting the
device.
• Install the consumer-adapted fuses.
• Do not connect the connector if strained.
3.4.1 Operation in areas at risk of explosion
WARNING
Do not connect the connector if strained
Sparks can be created, the plug is mounted under tension or replaced.
• If operated in explosive areas, the electrical data of the unit and the valid
local regulations and guidelines for the installation and operation of elec-
trical systems in explosive areas must be observed (e.g. DIN EN 60079).
• If units are used in potentially explosive areas, the personnel must receive
additional training or briefings or have a permit to work on explosion-protec-
ted units in potentially explosive systems.
• A CE-conform mains adapter with a slow 200 mA fuse only may be used in
the power supply circuit.
NOTICE!The outer ground connection must always be connected to the
protective potential equalisation or a similar local potential equalisation.
The ground terminal is suitable for connecting fine-wire conductors up to 4 mm2
or single-wire conductors up to 6 mm2.
(1) The assembly past is not part of the delivery scope nor is it a part of the accessories.

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
16 BA_EN_DE90
The earthing connection serves to discharge static electricity.
Earth terminal
Warning
WARNING - DO NOT CONNECT OR DISCONNECT EQUIPMENT UNDER VOLTAGE
Fig.10: Ground connection
3.4.2 Devices with switch outputs
3.4.2.1 3-conductor circuit
The device is connected as follows in a 3-wire switch as described below. The
admissible load / resistance is stated in the technical data. It is connected using
a prefabricated sensor connection cable (see accessories). Alternatively, a pre-
fabricated M12 connector can also be used.
NOTICE!The protection class of the housing can only be guaranteed, if an
IP65 connecting plug is used.
1 channel version
Δp1 V
in
GND
+AOut1
DE90
Channel 1 U
+-
Output 1
RL
Auxiliary energy
AC/DC
b
Ub
+
-
F1
1
3
4
(~)
(~)
2
-AOut1
Fig.11: 3-conductor circuit (1 channel)
2 channel version
V
in
GND
AOut2
DE90
Chan. 1 U
Chan. 2
+-
Output 1 Output 2
-
+
RLRL
Auxiliary energy
AC/DC
b
Ub
+
-
F1
Δp1
Δp2
AOut1
1
3
4
2
(~)
(~)
Fig.12: 3-conductor circuit (2 channel)

FISCHER Mess- und Regeltechnik GmbH Assembly | 3
BA_EN_DE90 17
3.4.2.2 M12 connector 1: auxiliary energy and analogue output
1 channel version
2 1
3 4
5
A
Fig.13: M12 plug 5-pin+bridge
PIN Signal Cable colour
1Operating voltage +UbBrown
2Analog output 1 -AOut1 White
3Operating voltage - UbBlue
4Analog output 1 +AOut1 Black
5Unused Grey
ACoding
2 channel version
2 1
3 4
5
A
Fig.14: M12 plug 5-pin
PIN Signal Cable colour
1Operating voltage +UbBrown
2Analog output 2 AOut2 White
3Operating voltage - UbBlue
4Analog output 1 AOut1 Black
5Unused Grey
ACoding
3.4.2.3 M12 connector 2: switch outputs
The number of switch outputs depends on the number of measuring ducts.
1 channel version 2 switch outputs
2 1
3 4
A
Fig.15: M12 plug 4-pin
PIN Signal Cable colour
1Switch output 1 SP1 Brown
2Switch output 2 SP2 White
3Switch output 2 SP2 Blue
4Switch output 1 SP1 Black
ACoding
2 channel version 4 switch outputs
1
7
6
5
4
3
2A
8
Fig.16: M12 plug 8-pin
PIN Signal Cable colour
1Switch output 1 SP1 White
2Switch output 1 SP1 Brown
3Switch output 2 SP2 Green
4Switch output 2 SP2 Yellow
5Switch output 3 SP3 Grey
6Switch output 3 SP3 Pink
7Switch output 4 SP4 Blue
8Switch output 4 SP4 Red
ACoding

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
18 BA_EN_DE90
3.4.3 Device with Modbus
DANGER
Auxiliary for ATEX devices
When selecting the power supply, bear in mind that it may be a potential ignition
source.
Take suitable safety precautions to prevent this risk.
Modbus IN
Modbus OUT
1
2
Fig.17: Replacement plate Mod-
bus
The devices with a Modbus interface do not have analog and switch outputs.
The replacement board is equipped with a 5-pin M12 flange connector for the
Modbus input and with a 5-pin M12 flange socket for the Modbus output.
The DE90 is usually connected to the Modbus RTU network as a so-called
slave to the Modbus RTU network. Up to 247 devices can be addressed in one
line network.
NOTICE!Star-shaped networks are not allowed.
MASTER DE90
1 2
DE90
1 2
DE90
1 2
Address 1 Address 2 Address 247
Bus termination
AC/DC
AC
M
Supply
1 2E
Modbus 5
Fig.18: Modbus RTU network
Communication is effected solely with the Modbus master. The connected
slaves only react to direct commands from the master, which is why communic-
ation between the slaves is not possible.
To guarantee fault-free data transmission, we recommend terminating the end
point of the Modbus RTU network with a 120 Ω resistor. This bus termination
resistance is available as an accessory.
3.4.3.1 Connection to an existing Modbus RTU network
It can be connected to an existing Modbus network via a conventional T-piece
(passive TAP).
MASTER
M
TAP
M
Slave
TAP
LT LT
M
Slave
TAP
DE90
1 2
Supply
1 2E
AC/DC
AC
Fig.19: Modbus connection

FISCHER Mess- und Regeltechnik GmbH Assembly | 3
BA_EN_DE90 19
3.4.3.2 Auxiliary energy supply
The following illustrations explain the principle of the power supply of the DE90
in the Modbus network. However the feeder nodes are not part of the delivery
scope and need to be installed by the operator himself.
BUS-D1
BUS-D0
BUS-R
AC/DC
AC
BUS-D1
BUS-D0
BUS-R
Ub +
Ub -
1
3
2
4
5
DE90
Master
+
Auxiliary energy
Feed
1
3
2
4
5
1
3
2
4
5
ST1 ST2
1
3
2
4
5
A
max. 2A
(~)
(~)
Fig.20: Main supply
Please note that the M12 plugs are approved for max. 2A. This value may
already be exceeded if there are more than 12 devices of type DE90. In this
case, an intermediate auxiliary energy feed should be provided at a suitable
place.
AC/DC
AC
BUS-D1
BUS-D0
BUS-R
Ub2 +
Ub2 -
1
3
2
4
5
DE90
Auxiliary energy 2
Feed
1
3
2
4
5
1
3
2
4
5
ST1 ST2
DE90
1
3
2
4
5
1
3
2
4
5
ST1 ST2
BUS-D1
BUS-D0
BUS-R
2
4
5
1
3
A
max. 2A
(~)
(~)
Ub +
Ub -
(~)
(~)
Fig.21: Intermediate supply
3.4.3.3 M12 plug 1: Modbus IN
2 1
3 4
5
A
Fig.22: M12 plug 5-pin
PIN Signal Cable colour
1Operating voltage +UbBrown
2Modbus BUS-D1 White
3Operating voltage - UbBlue
4Modbus BUS-D0 Black
5Modbus BUS-R Grey
ACoding

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
20 BA_EN_DE90
3.4.3.4 M12 plug 2: Modbus OUT
1 2
4 3
5
A
Fig.23: M12 bush 5-pin
PIN Signal Cable colour
1Operating voltage +UbBrown
2Modbus BUS-D1 White
3Operating voltage - UbBlue
4Modbus BUS-D0 Black
5Modbus BUS-R Grey
ACoding
3.4.4 USB port
DANGER
Open the housing for ATEX devices
ATEX devices may never be opened inside potentially explosive areas.
There is a micro USB connection for a USB stick inside the housing. The para-
meters can be secured and loaded or the firmware can be updated via this USB
interface. The device can be configured via this interface using the PC software
'inTouch'(2) .
The two lid screws need to be removed to open the housing.
Lid screw
PH1
Micro USB socket
0.5 Nm
Fig.24: USB port (fig. similar)
(2) see accessories