FISCHER FT90 User manual

II 3G Ex ec IIC T4 Gc
II 3D Ex tc IIIB T125°C Dc
Operating manual
FT90
Humidity and temperature measuring device
PRO-LINE®
with optional (differential) pressure measurement
09015247 • BA_EN_FT90 • Rev. ST4-D • 11/21 *09015247*

| Masthead FISCHER Mess- und Regeltechnik GmbH
2/108 BA_EN_FT90
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 2020
Version history
Rev. ST4-A 03/20 Version 1 (first edition)
Rev. ST4-B 08/20 Version 2 Ordering code changed
Rev. ST4-C 09/20 Version 3 Passwords
Rev. ST4-D 11/21 Version 4 Accessories (cable length for sensor changed)

FISCHER Mess- und Regeltechnik GmbH Table of contents
BA_EN_FT90 iii/108
Table of contents
1 Safety instructions .......................................................................................................... 6
1.1 General................................................................................................................................... 6
1.2 Personnel Qualification........................................................................................................... 6
1.3 Personnel Qualification........................................................................................................... 6
1.4 Risks due to Non-Observance of Safety Instructions............................................................. 6
1.5 Safety Instructions for the Operating Company and the Operator ......................................... 6
1.6 Safety Instructions for the Operating Company and the Operator ......................................... 7
1.7 Unauthorised Modification...................................................................................................... 7
1.8 Inadmissible Modes of Operation........................................................................................... 7
1.9 Safe working practices for maintenance and installation work............................................... 7
1.10Pictogram explanation ............................................................................................................ 8
2 Product and functional description ............................................................................... 9
2.1 Delivery scope........................................................................................................................ 9
2.2 Intended use........................................................................................................................... 9
2.2.1 Explosion hazard area classification.......................................................................................... 9
2.3 Function diagram.................................................................................................................... 10
2.4 Design and mode of operation ............................................................................................... 10
2.5 Device versions ...................................................................................................................... 11
2.5.1 Process connection.................................................................................................................... 11
2.5.2 Electrical connection .................................................................................................................. 11
2.5.3 ATEX model............................................................................................................................... 12
2.5.4 Type plate .................................................................................................................................. 12
3 Assembly.......................................................................................................................... 14
3.1 General................................................................................................................................... 14
3.2 Mounting in explosive areas ................................................................................................... 14
3.3 Process connection ................................................................................................................ 15
3.3.1 Replacement plates ................................................................................................................... 15
3.3.2 Cutting ring screw connections .................................................................................................. 16
3.4 Electrical connections............................................................................................................. 17
3.4.1 Operation in areas at risk of explosion....................................................................................... 17
3.4.2 Devices only with switch outputs ............................................................................................... 18
3.4.2.1 Circuit ......................................................................................................................................... 18
3.4.2.2 M12 connector 1: auxiliary energy and analogue output............................................................ 19
3.4.2.3 M12 connector 2: switch outputs ................................................................................................ 19
3.4.2.4 M12 connector 3: Sensor input................................................................................................... 19
3.4.3 Devices with switching and analog outputs ............................................................................... 20
3.4.3.1 Circuit ......................................................................................................................................... 20
3.4.3.2 M12 connector 1: auxiliary energy and analogue output............................................................ 21
3.4.3.3 M12 connector 2: switch outputs ................................................................................................ 21
3.4.3.4 M12 connector 3: Sensor input................................................................................................... 21
3.4.4 Device with Modbus................................................................................................................... 22
3.4.4.1 Connection to an existing Modbus RTU network ....................................................................... 22
3.4.4.2 Auxiliary energy supply............................................................................................................... 23
3.4.4.3 M12 plug 1: Modbus IN .............................................................................................................. 24
3.4.4.4 M12 plug 2: Modbus OUT .......................................................................................................... 24
3.4.4.5 M12 connector 3: Sensor input................................................................................................... 24

Table of contents FISCHER Mess- und Regeltechnik GmbH
iv/108 BA_EN_FT90
4 Start-up ............................................................................................................................. 25
4.1 Installation control................................................................................................................... 25
4.2 Switch on the measuring device............................................................................................. 25
4.2.1 Measured value display ............................................................................................................. 26
4.2.1.1 2-channel version T/rH ............................................................................................................... 26
4.2.1.2 3-channel version P/T/rH............................................................................................................ 27
4.2.1.3 Back lighting ............................................................................................................................... 28
4.2.2 Keyboard.................................................................................................................................... 28
4.3 Setup ...................................................................................................................................... 29
4.3.1 Set menu language.................................................................................................................... 29
4.3.2 Measuring point designation ...................................................................................................... 29
4.3.3 Configuration.............................................................................................................................. 29
4.4 Modbus RTU interface............................................................................................................ 29
5 Operation.......................................................................................................................... 30
5.1 First steps ............................................................................................................................... 30
5.1.1 Passwörter ................................................................................................................................. 30
5.1.2 Operating modes ....................................................................................................................... 30
5.1.3 Menu tree................................................................................................................................... 31
5.1.3.1 Login........................................................................................................................................... 31
5.1.3.2 Quick access .............................................................................................................................. 31
5.1.3.3 Configuration .............................................................................................................................. 32
5.1.3.4 Info.............................................................................................................................................. 36
5.1.3.5 Service........................................................................................................................................ 36
5.1.4 Navigation in the menu tree ....................................................................................................... 37
5.1.5 Path details ................................................................................................................................ 39
5.1.6 Input ........................................................................................................................................... 39
5.1.6.1 Text input.................................................................................................................................... 39
5.1.6.2 Value input.................................................................................................................................. 40
5.1.6.3 Selection of options .................................................................................................................... 42
5.2 Main menu.............................................................................................................................. 43
5.3 Login....................................................................................................................................... 44
5.3.1 Log in / log out ........................................................................................................................... 45
5.3.2 Timeout ...................................................................................................................................... 46
5.3.3 Manage users ............................................................................................................................ 46
5.3.3.1 User 1 ......................................................................................................................................... 47
5.3.3.2 Administrator .............................................................................................................................. 49
5.3.4 Reset passwords ....................................................................................................................... 49
5.4 Quick access .......................................................................................................................... 50
5.5 Configuration .......................................................................................................................... 52
5.5.1 Channels 1 to 3.......................................................................................................................... 53
5.5.1.1 Mode C1 ..................................................................................................................................... 55
5.5.1.2 Measurement C1 ........................................................................................................................ 56
5.5.1.3 Characteristic curve C1 (menu expansion) ................................................................................ 63
5.5.1.4 Number format C1 ...................................................................................................................... 70
5.5.1.5 Colour change C1....................................................................................................................... 71
5.5.2 Analog output............................................................................................................................. 77
5.5.2.1 Analog output 1 type................................................................................................................... 78
5.5.2.2 Analog output 1 assignment ....................................................................................................... 78
5.5.2.3 Signal limits ................................................................................................................................ 79

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5.5.3 Switch output ............................................................................................................................. 80
5.5.3.1 SP1 assignment ......................................................................................................................... 80
5.5.3.2 SP1 function ............................................................................................................................... 81
5.5.3.3 Switching function....................................................................................................................... 81
5.5.4 Display ....................................................................................................................................... 82
5.5.4.1 Language.................................................................................................................................... 83
5.5.4.2 Designation................................................................................................................................. 83
5.5.4.3 Measuring data display............................................................................................................... 83
5.5.4.4 Colour change assignment......................................................................................................... 84
5.5.4.5 LCD colour.................................................................................................................................. 85
5.5.4.6 LCD lighting ................................................................................................................................ 85
5.5.4.7 LCD contrast............................................................................................................................... 86
5.5.5 Modbus RTU.............................................................................................................................. 86
5.5.5.1 Baud rate .................................................................................................................................... 87
5.5.5.2 Data format................................................................................................................................. 87
5.5.5.3 Modbus address ......................................................................................................................... 88
5.5.5.4 Byte order ................................................................................................................................... 88
5.6 Info.......................................................................................................................................... 89
5.7 Service.................................................................................................................................... 89
6 Servicing........................................................................................................................... 91
6.1 Maintenance ........................................................................................................................... 91
6.2 Transport ................................................................................................................................ 91
6.3 Service.................................................................................................................................... 91
6.4 Disposal.................................................................................................................................. 91
7 Technical data.................................................................................................................. 92
7.1 General................................................................................................................................... 92
7.2 Input variables ........................................................................................................................ 92
7.2.1 Temperature and humidity ......................................................................................................... 92
7.2.2 Differential pressure................................................................................................................... 92
7.3 Output sizes............................................................................................................................ 93
7.4 Measuring accuracy ............................................................................................................... 94
7.4.1 Humidity ..................................................................................................................................... 94
7.4.2 Temperature .............................................................................................................................. 95
7.4.3 Differential pressure................................................................................................................... 95
7.5 Digital interfaces ..................................................................................................................... 96
7.6 Auxiliary energy ...................................................................................................................... 97
7.7 Operating conditions............................................................................................................... 97
7.8 Display.................................................................................................................................... 98
7.9 Construction design................................................................................................................ 98
7.9.1 Materials .................................................................................................................................... 98
7.9.2 Dimensional drawings................................................................................................................ 99
8 Order code........................................................................................................................101
8.1 Accessories ............................................................................................................................104
9 Attachments .....................................................................................................................105
9.1 EU Declaration of Conformity .................................................................................................105

1 | Safety instructions FISCHER Mess- und Regeltechnik GmbH
6/108 BA_EN_FT90
1 Safety instructions
1.1 General
This operating manual contains basic instructions for the installation, operation
and maintenance of the device that must be followed without fail. It must be
read by the installer, the operator and the responsible specialist personnel be-
fore installing and commissioning the device.
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.
1.3 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.
1.4 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.
1.5 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.

FISCHER Mess- und Regeltechnik GmbH Safety instructions | 1
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1.6 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.
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.
1.7 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.
1.8 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.
1.9 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 | Safety instructions FISCHER Mess- und Regeltechnik GmbH
8/108 BA_EN_FT90
1.10 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.

FISCHER Mess- und Regeltechnik GmbH Product and functional description | 2
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2 Product and functional description
2.1 Delivery scope
• Differential pressure transmitter FT90 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 FT90 is suitable for the measurement of humidity and temperature in neut-
ral gaseous media. Optionally, the device can be used to measure the pressure,
negative pressure, or differential pressure of neutral gaseous media.
Note the specifications in the technical data with regard to media compatibility.
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
Devices with the order code FT90 ## ## ## # 0 # 000 R1 # # are classified as
electrical equipment for use in potentially explosive areas zone 2 (gases and
vapours) and/or zone 22 (dusts).
Gas explosion protection
Designation as per Directive 2014/34/EU:
II 3G Ex ec IIC T4 Gc
Dust explosion protection
Designation as per Directive 2014/34/EU:
II 3D Ex tc IIIB T125°C Dc
-20°C ≤ T ≤ 60°C
amb

2 | Product and functional description FISCHER Mess- und Regeltechnik GmbH
10/108 BA_EN_FT90
2.3 Function diagram
Sensor 2
Display
þ û ÿ
Analog output 1
Switch output 1
Switch output 2
Switch output 3
Switch output 4
Temperature
Power
supply
24 V AC/DC
USB OTG RS485
Modbus
Analog output 2
Sensor 3
Humidity
µC
Options
Sensor 1
Differential pressure
Option
Analog output 3
Channel 1
Channel 2
Channel 3
Option
Fig.1: Function diagram
2.4 Design and mode of operation
Temperature and humidity measurement
The temperature and humidity measurement is based on a sensor chip with a
digital I2C bus interface. The analog measurement data is digitally converted
and linearised. The transmitted data is evaluated by the integrated electronics
and is transformed into a display, analog output, and up to four switch outputs
or output via the optional Modbus output.
Pressure measurement
The pressure measurement is based on a piezo-resistive sensor element that is
suitable for measuring overpressure, negative pressure, and differential pres-
sure. The pressures to be compared have a direct effect on a silicon membrane
equipped with a measuring bridge.
When the pressure is equal, the measuring membrane is in its idle state. If a
pressure difference occurs, the membrane is deflected and a resistance change
takes place on the attached measuring bridge. This change is evaluated by the
electronics integrated into the device and is transformed into a display, analog
output, and up to four switch outputs or is output via the optional Modbus out-
put.

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2.5 Device versions
2.5.1 Process connection
Cutting ring screw connection
1/8'' screw connection
O-ring
O-ring
CK screw connection
CK screw connection
Pneumatic
plug-in connection
FF90 temperature
and humidity sensor
lock-
screw
Humidity and temperature
measuring device
Humidity and temperature measuring device
with pressure measurement
Fig.2: Process connections
2.5.2 Electrical connection
Connector 1
Connector 2
Output signal
auxiliary energy
Switch outputs
Fig.3: Electric connections

2 | Product and functional description FISCHER Mess- und Regeltechnik GmbH
12/108 BA_EN_FT90
2.5.3 ATEX model
Earthing connection Conductive housing
Fig.4: ATEX model
2.5.4 Type plate
1
2
3
4
5
7
8
10
13
14
9
12
1615
11
18
Fig.5: Humidity/temperature type plate
17
1
2
3
4
5
6
7
8
10
9
12
11
4
3
5
13
14
1615
18
Fig.6: Pressure/humidity/temperature type plate

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1Conformity 2Device type (order code)
3Basic measuring range 4Set measuring range
5Output signal 6Overload capacity
7Auxiliary energy 8Production number
9Customer item number 10 ATEX marking
11 Special properties 12 Parameter number
13 Circuit diagram for connector 1 14 Circuit diagram for connector 2
15 Data for channel 1 16 Data for channel 2
17 Data for channel 3 18 Parameter number
Explanations of the symbols
Input
Output
Factory Setting
Production No.
Proof Pressure
Customers Art.no.
Parameter No.
CAL
Pmax
P#
M#
Para. #

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
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3 Assembly
3.1 General
The device is designed for installation on assembly plates or wall surfaces. A
pre-mounted 35 mm plastic assembly rail is supplied for this purpose. The at-
tachment screws are not included in the delivery.
Alternatively, the device can also be mounted to a 35 mm top-hat rail.
Fixing screw
Ø 3 ...4 mm
35mm top hat rail
mounting rail
1
2
Click
Fig.7: 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.

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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.
1. Differential pressure measurement
Higher pressure
lower pressure
2. Pressure measurement
Pressure
open
3.3.1 Replacement plates
The device is fitted with different replacement plates depending on the number
of measuring channels.
Differential pressure
Moisture and temperatureMoisture and temperature
Blind plug
Blind plug
Fig.8: 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.

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
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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.9: Process connection table
3.3.2 Cutting ring screw connections
wIn the case of cutting ring screw connections, incorrect installation of the
pressure lines can lead to the 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 only with a 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.10: Counter-hold for cutting ring screw connections
(1) The assembly paste is not part of the delivery scope nor is it included in the accessories.

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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 the device is operated in potentially explosive atmospheres, the electrical
data of the unit and the valid local regulations and guidelines for the installa-
tion and operation of electrical systems in potentially explosive atmospheres
must be observed (e.g. DIN EN 60079).
• If the device is used in a potentially explosive atmosphere, the personnel
must have received additional training/instruction and/or have obtained a
permit for working on explosion-proof devices in potentially explosive sys-
tems.
• 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.
The earthing connection serves to discharge static electricity.
Earth terminal
Warning
WARNING - DO NOT CONNECT OR DISCONNECT EQUIPMENT UNDER VOLTAGE
Fig.11: Earthing connection

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
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3.4.2 Devices only with switch outputs
3.4.2.1 Circuit
The device is connected as described below. The admissible load/impedance is
stated in the technical data. The connection is performed using a prefabricated
sensor connection cable (see the accessories). Alternatively, a prefabricated
M12 connector can be used.
NOTICE!The protection class of the housing can be guaranteed only if an
IP65 connecting plug is used.
Version dP/T/rH
V
in
GND
FT90
Channel 1 U
Channel 2
Auxiliary energy
AC/DC
b
Ub
+
-
F1
Δp
T
1
3
4
2
(~)
(~)
1
2
3
4
SP1
SP2
ST2
5
6
7
8
SP3
SP4
Switch output 1
Switch output 2
Switch output 3
Switch output 4
No connection
No connection
ST1
5No connection
Channel 3
%rH
FF90
Fig.12: 3-channel version
Version T/rH
V
in
GND
FT90
U
Channel 1
Auxiliary energy
AC/DC
b
Ub
+
-
F1
T1
3
4
2
(~)
(~)
1
2
3
4
SP1
SP2
ST2
5
6
7
8
SP3
SP4
Switch output 1
Switch output 2
Switch output 3
Switch output 4
No connection
No connection
ST1
5No connection
Channel 2
%rH
FF90
Fig.13: 2-channel version

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3.4.2.2 M12 connector 1: auxiliary energy and analogue output
2 1
3 4
5
A
Fig.14: 5-pin M12 connector
Pin Signal Cable colour
1Operating voltage + UbBrown
2Unused White
3Operating voltage - UbBlue
4Unused Black
5Unused Grey
ACoding
3.4.2.3 M12 connector 2: switch outputs
1
7
6
5
4
3
2A
8
Fig.15: 8-pin M12 connector
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
3.4.2.4 M12 connector 3: Sensor input
NOTICE!The operating voltage U+ is generated by FT90.
1 2
4 3
A
Fig.16: 4-pin M12 bush
Pin Signal Cable colour
1Operating voltage (internal) U+ Brown
2I2C bus SCL White
3Operating voltage (internal) GND Blue
4I2C bus SDA Black
ACoding

3 | Assembly FISCHER Mess- und Regeltechnik GmbH
20/108 BA_EN_FT90
3.4.3 Devices with switching and analog outputs
3.4.3.1 Circuit
The device is connected in a 3-wire circuit as described below. The admissible
load/impedance is stated in the technical data. The connection is performed us-
ing a prefabricated sensor connection cable (see the accessories). Alternatively,
a prefabricated M12 connector can be used.
NOTICE!The protection class of the housing can be guaranteed only if an
IP65 connecting plug is used.
Version dP/T/rH
V
in
GND
FT90
Channel 1 U
Channel 2
Auxiliary energy
AC/DC
b
Ub
+
-
F1
Δp
T
1
3
4
2
(~)
(~)
1
2
3
4
SP1
SP2
ST2
5
6
7
8
SP3
SP4
Switch output 1
Switch output 2
Switch output 3
Switch output 4
ST1
5
Channel 3
%rH
FF90
+ -
RL
+-
RL
+ -
RL
OUT2
+A
+A OUT1
+A OUT3
outp. 1 Outp. 2 Outp. 3
Fig.17: 3-channel version
Version T/rH
V
in
GND
FT90
U
Channel 1
Auxiliary energy
AC/DC
b
Ub
+
-
F1
T1
3
4
2
(~)
(~)
1
2
3
4
SP1
SP2
ST2
5
6
7
8
SP3
SP4
Switch output 1
Switch output 2
Switch output 3
Switch output 4
ST1
5
Channel 2
%rH
FF90
+ -
RL
+-
RL
OUT2
+A
+A OUT1
+A OUT3
Outp. 1 Outp. 2
No connection
Fig.18: 2-channel version