Installation manual for the EXTER series operator panels
Foreword
The EXTER operator panel is developed to satisfy the demands of human-machine
communication. Built-in functions such as displaying and controlling text, dynamic
indication, time channels, alarm and recipe handling are included.
The operator panel work, for the most part, in an object-oriented way, making it easy
to understand and use. The configuration operation of the panel is made in a personal computer, using the configuration tool Information Designer. The project is then
transferred and stored in the operator panel.
The operator panel can be connected to many types of automation equipment, such
as PLCs, servos or drives. In this manual the expression “the controller“ is used as a
general term for the connected equipment.
This manual explains how to install the operator panel. Please refer to the reference
manual for further information.
The information in this document is subject to change without notice and is provided as available at the time
of printing. Beijer Electronics AB reserves the right to change any information without updating this
publication. Beijer Electronics AB assumes no responsibility for any errors that may appear in this document.
Read the entire installation manual prior to installing and using this equipment.
Only qualified personnel may install, operate or repair this equipment. Beijer Electronics AB is not responsible
for modified, altered or renovated equipment.
Because the equipment has a wide range of applications, users must acquire the appropriate knowledge to use
the equipment properly in their specific applications.
Persons responsible for the application and the equipment must themselves ensure that each application is in
compliance with all relevant requirements, standards and legislation in respect to configuration and safety.
Only parts and accessories manufactured according to specifications set by Beijer Electronics AB may be used.
BEIJER ELECTRONICS AB SHALL NOT BE LIABLE TO ANYONE FOR ANY DIRECT, INDIRECT,
SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING FROM THE
INSTALLATION, USE OR REPAIR OF THIS EQUIPMENT, WHETHER ARISING IN TORT,
CONTRACT, OR OTHERWISE. BUYER'S SOLE REMEDY SHALL BE THE REPAIR,
REPLACEMENT, OR REFUND OF PURCHASE PRICE, AND THE CHOICE OF THE APPLICABLE
REMEDY SHALL BE AT THE SOLE DISCRETION OF BEIJER ELECTRONICS AB.
6.7 Cable and Bus Termination RS485................................................. 25
Beijer Electronics, MAEN774C
Table of Contents
Beijer Electronics, MAEN774C
Safety Precautions
1Safety Precautions
Both the installer and the owner and/or operator of the operator panel must read and
understand this installation manual.
1.1UL and cUL Installation
– This equipment is suitable for use in Class I, Division 2, Groups A, B, C and D
OR non-hazardous locations only. [Combinations of equipment in your system
are subject to investigation by the local Authority Having Jurisdiction at the time
of installation.]
– Maximum ambient temperature 40 °C when mounted horizontal or 50 °C when
mounted vertical.
– WARNING – EXPLOSION HAZARD – Do not disconnect equipment unless
power has been removed or the area is known to be non-hazardous.
– For Canada also AVERTISSEMENT – RISQUE D’EXPLOSION – AVANT DE
DECONNECTER L’EQUIPEMENT, COUPER LE COURANT OU
S’ASSURER QUE L‘EMPLACEMENT EST DESIGNE NON DANGEREUX.
– WARNING – EXPLOSION HAZARD - Substitution of components may
impair suitability for Class I, Division 2.
– For Canada also AVERTISSEMENT – RISQUE D’EXPLOSION – LA
SUBSTITUTION DE COMPOSANTS PEUT RENDRE CE MATERIEL
INACCEPTABLE POUR LES EMPLACEMENTS DE CLASSE I,
DIVISION 2.
– WARNING – EXPLOSION HAZARD – only UL and cUL approved expansion
units are allowed to be connected to the port designated “EXPANSION”. At the
moment there are no such units evaluated or allowed.
– WARNING – EXPLOSION HAZARD - Do not replace expansion unit unless
power has been switched off or the area is known to be non-hazardous.
– This product contains battery, this must only be changed in an area known to be
non-hazardous. Permitted types are shown in the section Technical Data.
– For use on a flat surface of a type 4X enclosure indoor use only.
– To make wiring connections to the power supply connector, use an AWG 28-12
cable and a tightening torque of min. 0.5 Nm.
Beijer Electronics, MAEN774C5
Safety Precautions
1.2General
– Read the safety precautions carefully.
– Check the delivery for transportation damage. If damage is found, notify the
supplier as soon as possible.
– Do not use the operator panel in an environment with high explosive hazards.
– The supplier is not responsible for modified, altered or reconstructed equipment.
– Use only parts and accessories manufactured according to specifications of the
supplier.
– Read the installation and operating instructions carefully before installing, using
or repairing the operator panel.
– Never allow fluids, metal filings or wiring debris to enter any openings in the
operator panel. This may cause fire or electrical shock.
– Only qualified personnel may operate the operator panel.
– Storing the operator panel where the temperature is lower/higher than
recommended in this manual can cause the LCD display liquid to congeal/become
isotopic.
– The LCD display liquid contains a powerful irritant. In case of skin contact, wash
immediately with plenty of water. In case of eye contact, hold the eye open, flush
with plenty of water and get medical attention.
– The figures in this manual serves an illustrative purpose. Because of the many
variables associated with any particular installation, the supplier cannot assume
responsibility for actual use based on the figures.
– The supplier neither guarantees that the operator panel is suitable for your
particular application, nor assumes responsibility for your product design,
installation or operation.
1.3During Installation
– The operator panel is designed for stationary installation on a plane surface, where
the following conditions are fulfilled:
• no high explosive risks
• no strong magnetic fields
• no direct sunlight
• no large, sudden temperature changes
– Install the product according to the accompanying installation instructions.
– Ground the product according to the accompanying installation instructions.
– Only qualified personnel may install the operator panel.
– Separate the high voltage, signal and supply cables.
– Make sure that the voltage and polarity of the power source is correct before
connecting the product to the power outlet.
– Peripheral equipment must be appropriate for the application and location.
6Beijer Electronics, MAEN774C
Safety Precautions
1.4During Use
– Keep the operator panel clean.
– Emergency stop and other safety functions may not be controlled from the
operator panel.
– Do not use too much force or sharp objects when touching the keys, touch screen
etc.
1.5Service and Maintenance
– Only qualified personnel should carry out repairs.
– The agreed warranty applies.
– Before carrying out any cleaning or maintenance operations, disconnect the
equipment from the electrical supply.
– Clean the display and surrounding front cover with a soft cloth and mild
detergent.
– Replacing the battery incorrectly may result in explosion. Only use batteries
recommended by the supplier.
1.6Dismantling and Scrapping
– The operator panel or parts thereof shall be recycled according to local regulations.
– The following components contain substances that might be hazardous to health
and the environment: lithium battery, electrolytic capacitor and display.
Beijer Electronics, MAEN774C7
Safety Precautions
8Beijer Electronics, MAEN774C
2Installation
2.1Space Requirements
– Installation plate thickness: 1.5 - 9.0 mm (0.06 - 0.35 inch)
– Space requirements when installing the operator panel:
100 mm
(4.0 inch)
228 mm
(8.98 inch)
50 mm
(2.0 inch)
100 mm
(4.0 inch)
302 mm
(11.89 inch)
50 mm
(2.0 inch)
Installation
100 mm
(4.0 inch)
58 mm
(2.28 inch)
Caution
The openings on the enclosure are for air convection. Do not cover these
openings.
2.2Installation Process
1. Unpack and check the delivery. If damage is found, notify the supplier.
Panel cut out264.5 x 206.0 mm
(10.41 x 8.11 inch)
x13
Note:
Place the operator panel on a stable surface during installation.
Dropping it or letting it fall may cause damage.
2. Place the panel cut out where the operator panel is to be situated, draw along the
outer sides of the holes and cut according to the markings.
Beijer Electronics, MAEN774C9
Installation
3. Secure the operator panel in position, using all the fastening holes and the
provided brackets and screws:
x 13
0.5 - 1.0 Nm
4. Connect the cables in the specified order.
A
Use an M5 screw and a grounding conductor (as short as possible)
B
with a cross-section of minimum 2.5 mm
C
D
Caution
Ensure that the operator panel and the controller system have the
same electrical grounding (reference voltage level), otherwise errors
in communication may occur.
2
.
Caution
- Use only shielded communication cables.
- Separate high voltage cables from signal and supply cables.
Caution
- The operator panel must be brought to ambient temperature
before it is started up. If condensation forms, ensure that the
operator panel is dry before connecting it to the power outlet.
- Ensure that the voltage and polarity of the power source is correct.
Power
CFCARD
B
1
Controller
RS422/RS485
RS232
C
24V DC
24V DC
D
A
Ethernet
5. Carefully remove the laminated film over the operator panel display, to avoid
static electricity that could damage the panel.
10Beijer Electronics, MAEN774C
2.2.1Mode Switches
1
24VDC
CF CARD
COM 1
RS422
RS485
COM 2
RS232
10/100
EXPANSION
BUSY
MODE
1234
ON DIP
MODE
1234
ON DIP
All mode switches must be in OFF position during operator panel use.
The mode switches should not be touched unless by qualified personell.
Installation
2.2.2Connections to the Controller
For information about the cables to be used when connecting the operator panel to
the controller, please refer to the help file for the driver in question.
2.2.3Other Connections and Peripherals
– Cables, peripheral equipment and accessories must be suitable for the application
and its environment. For further details or recommendations, please refer to the
supplier.
Caution
When using a compact flash card, do not remove the card when the busy
indicator is illuminated.
Beijer Electronics, MAEN774C11
Installation
12Beijer Electronics, MAEN774C
Technical Data
3Technical Data
ParameterEXTER T100
Front panel, W x H x D 302 x 228 x 6 mm
Mounting depth58 mm (158 mm including clearance)
Front panel sealIP 66
Rear panel sealIP 20
Keyboard material/
Front panel
Reverse side materialPowder-coated aluminum
Weight2.1 kg
Serial port RS422/
RS485
Serial port RS232C9-pin D-sub contact, male with standard locking screws 4-40
EthernetShielded RJ 45
USBHost type A (USB 1.1), max output current 500mA
CF-slotCompact flash, type I and II
Flash memory for
application
Real time clock±20 PPM + error because of ambient temperature and supply
Real time clock
battery
Power consumption at
rated voltage
DisplayTFT-LCD. 800 x 600 pixels, 64K color.
Active area of display,
W x H
FuseInternal DC fuse, 3.15 AT, 5 x 20 mm
Power supply+24V DC (20 - 30V DC). Power supply connector.
Ambient temperatureVertical installation: 0 ° to +50 °C
Storage temperature-20 ° to +70 °C
Relative humidity5 - 85 % non-condensed
CE approvalsNoise tested according to EN61000-6-4 emission and
UL, cUL approvals
(when procuct or
packing is marked)
DNVYes
NEMA4x indoor use only
* See section Chemical Resistance for more information.
Touch screen: Polyester on glass, 1 million finger touch
operations. Overlay: Autotex F157 or F207 *.
25-pin D-sub contact, chassis-mounted female with
standard locking screws 4-40 UNC.
UNC.
Device type B (USB 1.1)
12 MB (incl. fonts)
voltage. Total maximum error: 1 min/month at 25 °C
Temperature coefficient: 0.004 ppm/°C
CR2450 (UL and cUL: Sanyo or Panasonic)
Minimum lifetime: 3 years
Normal: 0.5 A
Maximum: 1.0 A
CCFL backlight lifetime at the ambient temperature of
+25 °C: >50,000 h.
211.2 x 158.4 mm
CE: The power supply must conform with the requirements
according to IEC 60950 and IEC 61558-2-4.
UL and cUL: The power supply must conform with the
requirements for class II power supplies.
Horizontal installation: 0 ° to +40 °C
EN61000-6-2 immunity.
UL 1604 Class I, Div 2 / UL 508 / UL 50 4x indoor use only
2
Beijer Electronics, MAEN774C13
Technical Data
14Beijer Electronics, MAEN774C
Chemical Resistance
4Chemical Resistance
4.1Metal Casing
The frame and casing material is powder-coated aluminum. This powder paint
withstands exposure to the following chemicals without visible change:
Acetic acid 10%Phosphoric acid 4%
Citric acid 10%Phosphoric acid 10%
DieselSea water
Distilled waterSodium chloride 2%
Edible oilSodium chloride 20%
Fuel oilSulphuric acid 20%
Hydrogen peroxide 3%Tap water
The powder paint shows limited resitance to the following chemicals at room
temperature:
ButanolNitric acid 3%
Hydrochloric acid 5%Nitric acid 10%
Isopropyl alcoholPhosphoric acid 43%
Na-hypochlorite 10%Turpentine
Note:
If exposure to any of the above chemicals is demanded, it is recommended to first test
the chemical on an “invisble” spot of the metal casing.
The powder paint shows little or no resistance to the following chemicals at room
temperature:
Acetic acid, conc.Methyl-ethyl ketoneToluene
AcetoneNitric acid 30%Trichlorethylene
Ammonia 5%PhenolXylene
Ammonia, conc.Sodium hydroxide 5% 97 octan unleaded petrol
Ethyl acetateSodium hydroxide 30% 98 octan leaded petrol
4.2Touch Screen and Overlay
4.2.1Autotex F157/F207
Autotex F157 or F207 covers the overlay surrounding the touch screen.
Solvent Resistance
Autotex F157/F207 withstands exposure of more than 24 hours duration under DIN
42 115 Part 2 to the following chemicals without visible change:
1
Acetonitrile
Ajax / Vim in solutionEthanolPotassium ferricyanide
Alkalicarbonate solution
Ammonia (<40%)
Beijer Electronics, MAEN774C15
1
Diesel Downey / Lenor
1
GlycerinePotassium hydroxide (<30%)
GlycolPure Turpentine
Phosphoric acid (<30%)
Chemical Resistance
Acetic acid (<50%)
Ariel powder in solution
1
Bleach
Castor oilMethanolTrichloroacetic acid (<50%)
Caustic soda (<40%)
Cutting oilParaffin oil
Cyclohexanol
Diacetone alcohol
1
Extremely faint glossing of the texture was noted.
1
Gumption
1
Hydrochloric acid (<36%)Sulfuric acid (<10%)
Linseed oilTomato ketchup
Nitric acid (<10%)White Spirit
Persil powder in solution
Petroleum spirit
1
1
1
SBP 60/95
Windex
Wisk
-
1
1
Autotex withstands DIN 42 115 Part 2 exposure of up to 1 hour duration to glacial
acetic acid without visible change.
Autotex is not resistant to high pressure steam at over 100 °C or the following
chemicals:
Concentrated mineral acidsBenzyl alcohol
Concentrated caustic solutionMethylene chloride
Outdoor Use
In common with all polyester based films Autotex F157/F207 is not suitable for use
in conditions of long term exposure to direct sunlight.
4.2.2Touch Screen Surface
The touch screen surface on the panel withstands exposure to the following solvents
without visible change:
SolventsTime
Acetone10 minutes
Isopropanol10 minutes
Toluene5 hours
4.2.3Autoflex EB
It is recommended to use the Autoflex EB touch display protection film, that can be
ordered from Beijer Electronics.
Solvent Resistance
Autoflex EB withstands exposure to the same chemicals as Autotex F157 or F207
according to section Autotex F157/F207.
Outdoor Use
In common with all polyester based films Autoflex EB is not suitable for use in
conditions of long term exposure to direct sunlight.
16Beijer Electronics, MAEN774C
Operator Panel Drawings
5Operator Panel Drawings
5.1Communication Ports
RS-232
RS-422/485
USB
RS-422
RS-485
Ethernet
Drawing No. S-5005, Date 2004-10-27
Beijer Electronics, MAEN774C17
Operator Panel Drawings
5.2EXTER T100 Outline
Drawing No. S-5113, Date 2004-10-26
18Beijer Electronics, MAEN774C
Additional Installation Tips
6Additional Installation Tips
When experiencing communication problems in for example noisy environments or
when operating close to temperature limits, the following recommendations are to be
noticed.
6.1Grounding the Operator Panel
Door
Operator panel
1
Ferrite core
6
3
2
5
4
Mounting plate in the cabinet
Power supply
24 V DC
1. The operator panel’s mounting clamps do not provide a secure grounding connection between the panel and the device cabinet.
2. Connect a 2.5 mm
2
wire between the operator panel’s quick-connect plinth and
the panel chassis.
2
3. Connect a 6 or 4 mm
wire or grounding braid between the panel’s chassis and
the closest grounding point on the door.
4. Connect a strong but short grounding braid between the door and the device
cabinet.
5. Twist the cables onto the 24 V DC feed.
6. A ferrite core suppresses disturbances to the 24 V feed.
2 turns around the ferrite core provide 4 times the suppression of 1 turn.
3 turns around the ferrite core provide 9 times the suppression of 1 turn.
Remember:
The grounding wires should be short and the conductor should have a large area.
A long, thin grounding wire has a very high impedance (resistance) at high frequencies
and will not guide disturbances to the ground.
Multi-wire conductors are better than single wire conductors with the same area.
A braided conductor wire with the same area is even better.
The best is a short, thick grounding braid.
Beijer Electronics, MAEN774C19
Additional Installation Tips
6.2Ethernet Connection in the Panel
Industrial Ethernet
RJ45
RJ45
RJ45
RJ45
Operator panel
RJ45
1
2
Operator panel
RJ45
Operator panel
RJ45
Operator panel
RJ45
Shielded
0.1 uF
250 V
3
4
1-1
2-2
3-3
8-8
Short and
unshielded
5
1. In some industrial units for Ethernet, the RJ45 contact’s shield is connected to
the chassis via a capacitor.
2. The operator panel’s Ethernet shield is directly connected to the chassis.
Check whether the other Ethernet unit has its shield directly grounded or grounded
via a capacitor.
In many cases, connecting the shielded Ethernet cabling to the chassis at both ends
is inappropriate. Hum or grounding loops can occur. Unshielded cabling may even
result in fewer communication errors.
A good solution may be to use a shielded Ethernet cable, but to connect the shield at
one end only.
3. One option is to break the shield.
4. A more elegant method is to expand the shielded Ethernet cabling with a piece
of unshielded Ethernet cable.
5. You can ground the shield via an external 0.1 uF/250 V plastic capacitor. This
will connect the HF transients to the ground.
20Beijer Electronics, MAEN774C
Additional Installation Tips
6.3To Achieve Better EMC Protection
– Initially, use the original cabling from Beijer Electronics primarily.
– Use shielded cables for RS232 communication.
– Use twisted pair and shielded cabling for RS422 and RS485.
– Use the cabling intended for the bus type; Ethernet, Profibus, CC-Link, CAN,
Device Net etc.
– Install and connect according to applicable specifications for the relevant bus stan-
dard.
– Use shielded cabling for Ethernet, preferably with foil + braided shield.
– D-sub covers should be shielded, and the shield should be connected to the cover
360 ° where the cable comes in.
– Connect the shield at both ends.
Shielded cable
0.1 uF/250 V
Ground plane 1Ground plane 2
Not same potential
Ground plate
With longer distances, there is a risk that the ground potential may be different. In
that case, the shield should only be connected at one end. A good alternative is to
connect the other end of the shield to the ground via a 0.1 uF/250 V plastic capacitor.
Both ends are then connected to the ground in terms of HF, but only connected to
the ground at one end in terms of LF, thus avoiding the 50 Hz grounding loops.
Metal cabinetMetal cabinet
Terminal or
connector
Ter m i n a l o r
connector
Ground plate
in another building
Cable clamp
in steel
Short distance
EMC cable gland
Shielded cableShielded cable
Plastic cable gland
– Use an EMC cable gland or regular plastic cable gland, remove the outer jacket
and connect the shield to the installation plate with a 360 ° metal cable clamp.
– Place the 24 V DC and communications cabling in one cable trunk/cable duct and
230/380 V AC in another. If the cables need to be crossed, cross them at 90 ° only.
Avoid combining the cabling for stronger 24 V DC outputs with the communi-
cation cabling.
– Ferrite cores that are snapped onto the shielded cabling may remove minor distur-
bances. Large ferrite pieces that are snapped onto unshielded cabling and where
the wires go 2-4 times around the cores are approximately 5-25 times more effi-
cient.
Beijer Electronics, MAEN774C21
Additional Installation Tips
6.4Ambient Temperature
The maximum ambient temperature for the operator panel is provided in the
specifications. The ambient temperature refers to the temperature in the device
cabinet which cools the panel’s electronics.
To p
50
Operator
panel
° inside
Power
30
°C outside
Middle
° inside
45
Bottom
40
° inside
Power
Power
Axial fan
120x120 mm
Airflow
5354
In most cases, the ambient temperature for the operator panel is significantly higher
than the device cabinet’s ambient temperature.
If the cabinet is tall and there are a number of heat-generating devices, the
temperature at the top of the cabinet will be considerably higher than the theoretical
temperature increase that would be expected. All electronics are sensitive to heat. The
lifespan of an electrolytic capacitor is cut in half with an 8-10 ° increase in
temperature. A 15-20 ° temperature increase results in a quarter of the lifespan etc.
Rittal has a good program for estimating the anticipated average temperature in the
cabinet as well as a large program for controlling the temperature in the device
cabinet.
2
An enamel-coated steel cabinet has a radiant heat value of 5.5 W/m
and degrees C.
Installing a fan inside the cabinet will even out the temperature, while moving air
provides considerably better cooling than still air. A suitable fan is a 120 x 120 mm
axial fan, available in 24 V DC, 115 and 230 V AC.
Install the fan so that it sits in the cooler area and will blow cold air against the
operator panel. If the fan is mounted at the top and sucks air upwards, the fan’s
ambient temperature will be higher = shorter lifespan.
A good fan with a ball-bearing mounting has an expected lifespan of at least 40,000
hours (not a guaranteed lifespan) at 40 °C. This corresponds to at least 4 years of
continuous use. If a thermostat is installed, the fan only needs to come on when
needed.
Large graphic terminals draw only one fifth of the current when the background
lighting is off. The loss effect drops from e.g. 25 W to only 5 W.
The operator panel’s loss effect = supply voltage x current. Virtually no power goes
to external users and no loss effects due to inputs.
22Beijer Electronics, MAEN774C
6.5Safety
Most of the operator panels are fed with 24 V DC.
Power supply
230 V AC to 24 V DC
1
Power supply
230 V AC to 24 V DC
2
Power supply
230 V AC to 24 V DC
3
+24 V
0 V
4
+24 V
0 V
4
Distance?
+24 V
0 V
4
230 V AC
Operator panel
Operator panel
Operator panel
Small controller with expansion unit
COM1
COM100
Ch0
Ch1
Ch100
Ch101
5355
Additional Installation Tips
1. If you use a power supply that meets safety standards and only feeds the operator
panel, there is no problem.
2. However, if you have a 24 V unit that also feeds other units, there is reason to be
cautious.
The operator panel does not have insulation that meets safety requirements in
the event of a potential short circuit between 230 V AC and 24 V DC. It is
assumed that the 24 V feed is secure, for example, SELV according to
EN 60950 (protection against electric shock) and UL 950.
Example:
Here is an example that explains why a secure 24 V DC feed can be ruined by mixing 24
V relay contacts with 230 V AC relay contacts in a smaller controller. Check that the
“clearances and creepage distances between 24 V DC and 230 V AC fulfill EN 60950 or
UL 950”. If not, input a separate 24 V unit into the operator panel.
3. If there is a substantial distance between the relay contacts for 24 V DC and
230 V AC, it is OK to use the same 24 V devices for all feeds.
4. Connect 0 V on the 24 V feed to the ground. This offers three advantages:
–Safety is increased. The 24 V feed will not be live in the event of a faulty connec-
tion or short circuit between 0 V (24 V) and 230 V phase.
–Transients on the 24 V feed are connected to the ground.
–No risk that the 24 V feed is at a high level in relationship to the ground. This is
not unusual since there is high static electricity.
Beijer Electronics, MAEN774C23
Additional Installation Tips
6.6Galvanic Isolation
+24 V DC
0 V
Filter
DC/DC
galvanic isolation
1.5 m
Internal electronic
VCC
0 V (GND)
RS422/485RS232USBUSB
DC/AC
Ethernet
CFL
5356
The operator panel has galvanic isolation against the 24 V DC feed but no galvanic
isolation between the communication ports for RS232, RS422/485 and USB. Only
the Ethernet connection has galvanic isolation.
Operator panel
RS422 RS232 USB
PC
**
**
*
Not same ground potential
* = Internal 0 V (GND) connection
Modular controller
CPU COM COM2Power
***
Printer
*
PC
When a PC is connected to the panel, the panel’s internal 0 V (GND) will be
connected to the protective ground via the PC.
A number of USB devices can have the shield connected together with the protective
ground. Here, the panel’s 0 V (GND) is connected to the protective ground when,
for example, a USB memory stick, keyboard or similar device is plugged in.
If a number of units are connected that have a 0 V and a ground connection, and
these are connected to various grounding points, there is a substantial risk of
problems. Grounding currents go through communication cables, the rear plate of
the controller, and internally in the operator panel, and can cause errors.
Use external units to improve communication and achieve galvanic isolation.
Westermo has good industry-standard insulators that are also insulated from the 24
V DC feed.
Note:
It is very important to make sure that the 24 V feed in the external insulation unit is
not connected to one of the communication outlets. If it does not have 100% insulation
against the 24 V feed, disturbances and grounding currents from the 0 V on the 24 V
side will disrupt communication.
Using this type of unit solves one problem but creates a larger problem!
A substandard installation may work now, but problems may arise when other devices
are connected.
24Beijer Electronics, MAEN774C
Additional Installation Tips
6.7Cable and Bus Termination RS485
– Use shielded and twisted pair cable.
2
The pair capacitance may not exceed 52.5 pF/m and area at least 0.25 mm
24), if you want to use the maximum transfer distance and maximum transfer
speed.
– 0 V, the reference voltage for communication should be included in the cabling.
With two-way communication use two pairs; one pair for communication and
one pair for 0 V.
– The shield must be grounded at one end. The other end is usually grounded, but
with longer distances or when there is a difference in the ground potential, the
shield should be connected to the ground via 0.1 uF/250 V plastic capacitor to
prevent ground current in the braided shield.
A number of manufacturers recommend that the shield be grounded at each node.
Various manufacturers have different systems for bus termination. The RS485
standard does not describe how the “Fail Safe” function would be carried out, just
that the system should be able to handle the error.
Depending on the recipients’ design, the bus wires may be on the same level or
require pull-up or pull-down to ensure that no faulty signals are detected when the
bus is in resting mode (all transmitters are disconnected).
Inside operator panel
+5 V
+5 V
123
1K
120 ohm
1K
0 V
120 ohm
(120 ohm)
1K
1K
(AWG
0 V
0 V
4
CAB8
Operator
panel
RS422
+5 V
0 V
0 V
VCC
CAB8
2.65 V
2.35 V
VCC
1K
120 ohm
1K
Bus
RS485
0 V
0 V
Shield
Bus termination
5358
1. Some (older) operator panels had pull-up and pull-down resistance except for
the actual bus termination at 120 ohm, similar to Westermo and Profibus.
2. Newer panels have another type of recipient, so-called built-in “Fail Safe”, where
simple bus termination resistance is sufficient.
If other nodes on the RS485 network require pull-up and pull-down and the
operator panel is at one end of the loop, one of the following procedures can be
carried out:
3. Connect two 1k/0.25 W resistors in the 25-pole D-sub contact. Set jumper pins
6-19.
4. Use CAB8. It offers the option of bus termination with pull-up/-down. It is also
easy to connect the bus cable via the screw terminal block.