Drehmo i-matic User manual

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 1 of 18
Prepared by: Ste
DREHMO

i - Matic
Electrical actuator with integral controls
Supplementary operating manual for actuators with MODBUS interface
part number: 166 671
Installation Manual Version 03
Operating Manual Date: Oct. 18
th
, 2006
INFORMATION
This installation manual should only be used in conjunction with the operating manual for drives!
This manual must be kept for future use.
Compact plug Electronic housing
Local controls
Motor
Gearbox
Drive output
Handwheel
Modbus redundant interface electronic
built in the electronic housing
MODBUS

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 2 of 18
Prepared by: Ste
Table of contents
1 Introduction.................................................................................................3
2 Interface technology ...................................................................................3
2.1 Physical interface ....................................................................................................3
2.2 Supported function codes ......................................................................................4
2.3 Data model ...............................................................................................................4
2.3.1 Accesses for master input data ( actuator feedback signals) .................................................5
2.3.2 Accesses for master output data ( actuator command signals)..............................................8
2.4 Parameterisation ...................................................................................................10
2.4.1 Communication settings – addresses, baud rate, parity........................................................10
2.4.2 Number of channels – bus profile.............................................................................................10
2.4.3 Redundancy modes – line redundant vs. master redundant .................................................10
2.4.4 Function Fail-Safe – Timeout setting........................................................................................10
2.4.5 Fault messages ...........................................................................................................................11
2.5 Electrical connection ............................................................................................12
2.5.1 Actuators i-Matic for normal operation – DiM-X0X..................................................................12
2.5.1.1 Compact plug assembly ........................................................................................................12
2.5.1.2 Bus termination......................................................................................................................14
2.5.1.3 Grounding of the cables´ shields in case of copper cable use..............................................14
2.5.1.4 Interface with fibre optic connection ......................................................................................15
2.5.2 Actuator i-Matic for Ex-Zone acc. ATEX device category 2 G – DiM-X1X.............................16
2.5.2.1 Connection with copper cable ...............................................................................................16
2.5.2.2 Connection with fibre optic cable...........................................................................................17
2.5.2.2.1 Setting of transmission power ...........................................................................................17
2.6 Interface to external sensor - process inputs .....................................................18

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 3 of 18
Prepared by: Ste
1 Introduction
This document describes the expansion of modbus RTU functionality for i-Matic actuator.
2 Interface technology
2.1 Physical interface
The physical interface is in accordance to the MODBUS over Serial Line Specification & Implementation guide
that can be found on the following web site: http://www.modbus.org/
The physical interfaces uses 2-wire RS485.
The following parameters are possible for the communication configuration:
Baud rates:
38400 bit/s
19200 bit/s
9600 bit/s
4800bit/s
2400bit/s
1200bit/s
600bit/s
300bit/s
The parity can be configured as follows:
parity none, with two stop bits,
parity even, with one stop bit,
parity odd, with one stop bit
The interface card has two separate 2-wire RS485 modbus channels. The baud rate and parity settings are
common for both channels. Each of the channels can be assigned an individual slave address in the range of
1 to 247 (different addresses are possible for test-purposes on a single master).
Broadcast messages are not supported.
In case of a redundant connection, the slave device decides itself about the channel priority. Only the
commands of the high priority channel are executed. For maintenance reasons there is a feedback bit for the
channel quality of each channel and a command bit to change the channel priority.
The physical connection is done on a separate interface board mounted in the compact plug. The shield of the
cables have to be fixed on the according strain relieves on this interface board. For each channel there exists
separate screw-terminals for the incoming and outgoing signals and a dipswitch for the optional termination of
the lines. Furthermore there are dipswitches for the shield connection of incoming or outgoing cables to
ground potential.

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 4 of 18
Prepared by: Ste
2.2 Supported function codes
Among the list of possible modbus functions as described in the modbus guidelines, the following function
codes are supported:
FC 01 Read Coil Status read single bit of master output data (command check)
FC 02 Read Input Status read single bit as input to master (bit feedback)
FC 03 Read Holding Registers read back of master output data as integer (command check)
FC 04 Read Input Registers read data as input to master (word feedback)
FC 05 Force Single Coil write single bit of master output data (command)
FC 06 Preset Single Register write single data of master output data (command)
FC 15 Force Multiple Coils write multiple bit of master output data (commands)
FC 16 Preset Multiple Registers write multiple data of master output data (commands)
FC 17 Report Slave ID Read TAG/KKS
2.3 Data model
The discrete single bit command and status bits for the actuator are mapped in a linear addressable structure.
Each command or status bit can be accessed individually. The commands are also addressable as single or
multiple words.
The reserved addresses for input and output data are as follows:
Coil addresses: range 1 (Hex 0x01 to 512 (Hex 0x200) results in 512 coils reserved
Register addresses: range 513 (Hex 0x201) to 544 (Hex 0x220) results in 32 registers reserved

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 5 of 18
Prepared by: Ste
2.3.1 Accesses for master input data ( actuator feedback signals)
The following table gives detailed information about the addresses of the actuator feedback signals.
Register
Bit
Coil
Signal
Meaning
0x201 0..7 1..16 Position value Low-Byte 0...1000ppt actual position value
8..15 Position value High-Byte
0x202 0 17 General fault signal 1 General fault signal 1 is active
1 18 General fault signal 2 General fault signal 2 is active
2 19 Phase failure One of the three phases has failed
3 20 Failure internal 24 V DC Only possible in case of external supply
4 21 Failure externally supplied 24 V
DC
Only possible in case of external supply
5 22 Torque in OPEN direction Max. torque in the OPEN direction
exceeded
6 23 Torque in CLOSED direction Max. torque in the CLOSED direction
exceeded
7 24 Drive in fail-safe Drive is in the fail-safe mode
8 25 Drive moves to OPEN (only
statically)
Movement in direction to OPEN position
signal
9 26 Drive moves to CLOSED (only
statically)
Movement in direction to CLOSE position
signal
10 27 Drive in end of travel position
OPEN
End of travel message only acc. to
position
11 28 Drive in end of travel position
CLOSED
End of travel message only acc. to
position
12 29 Drive in end of travel position
OPEN+Drehmo
End of travel message only if path and
torque
13 30 Drive in end of travel position
CLOSED+TORQUE
End of travel message only if path and
torque
14 31 Motor too hot Signal excess temperature motor
15 32 Drive in the remote mode Display of the operating mode
0x203 0 33 Drive in the local mode Display of the operating mode
1 34 Drive locally controlled Drive is locally controlled
2 35 Activation of discrete commands A remote command OPEN or CLOSE
can be given (Automatic mode = 0)
3 36 Drive in the learn mode Display of the operating mode
4 37 Locking Parameter setting for remote command
5 38 Torque limit deactivation in OPEN Parameter setting for deactivation
6 39 Torque limit deactivation in
CLOSED
Parameter setting for deactivation
7 40 Start-up bridging in OPEN active Parameter display
8 41 Start-up bridging in CLOSED
active
Parameter display
9 42 Local_ind = NOT Remote Drive is not in the remote mode
10 43 Emergency travel active Status indication
11 44 Approach fail-safe position Parameter display
12 45 Pulse generator active Parameter display
13 46 Intermediate position 1 Message active between Z and ZS 1
14 47 Intermediate position 2 Message active between ZS 2 and
OPEN
15 48 Drive does not start Warning message

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 6 of 18
Prepared by: Ste
Register
Bit
Coil
Signal
Meaning
0x204 0 49 Torque warning OPEN Torque higher than torque warning level
set
1 50 Torque warning CLOSED Torque higher than torque warning level
set
2 51 No signal of reference value If imxx5, message if no reference value
3 52 Hardware fault Warning message
4 53 Combined sensor defective Warning message
5 54
system check error
During self-check the electronic unit has
detected an error. The unit then performs
a reset and tries to enter the state fail-
safe. The indication can be cleared by
using the acyclic bit „Reset system test
error“ in slot 1 index 240, or by using the
local reset in system>reset, or by a
power off on cycle. The kind of error
(refer to operating manual of i-matic) can
be read out by using the acyclic service
“system test error code” in slot 1 index
195 or the system entry under actual
value diagnosis on the local control
station. This indication is important for
safety related systems, if due to an error
the system needs to be brought to a safe
state.
6 55 Maintenance required Perm. operating data are exceeded
7 56 Actuator is served Logged in user is specialist or
manufacturer for service reasons
8 57 Regulating time too long Regulating time longer than max. running
time
9 58 Max. valve stroke exceeded Regulating distance longer than stroke of
valves
10 59 Hand wheel operation Actuators hand wheel is in usage
11 60 Rotation monitor Set if rotation direction is wrong
12 61 Data exchange channel 1 Data exchange on channel 1 active
13 62 Data exchange channel 2 Data exchange on channel 2 active
14 63 Channel 1 primary Channel 1 commands are in use due to
highest channel priority
15 64 Channel 2 primary Channel 2 commands are in use due to
highest channel priority
0x205 0..15 65..80 Torque value 0...1000ppt of the torque value at power
output
0x206 0..7 81..96 Position value low byte 0...1000ppt of analogue input 1
8..15 Position value high byte
0x207 0..7 97..112 Position value low byte 0...1000ppt of analogue input 2
8..15 Position value high byte
0x208 0 113 Process input 1 State of digital input 1
1 114 Process input 2 State of digital input 2
2 115 Process input 3 State of digital input 3
3 116 Process input 4 State of digital input 4
4 117
5 118
6 119
7 120
8..15 121..128
0x209..
0x220
129..512
In order to access the feedback signals, the function codes FC 05 (Force Single Coil) or FC 06 (Preset Single
Register) have to be used. The following tables give telegram examples for these function codes.

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 7 of 18
Prepared by: Ste
telegram example FC02 read 128 bit as input to master (128 bit feedback)
Request
C8 02 00 00 00 80 68 33
Checksum
number of inputs (discrete feedback bits - 128)
database address (decimal 0)
function code 02 read discrete inputs (discrete feedback)
slave address 200 in example
Response
C8 02 10 C4 03 0F 00 84 42 A0 50 00 00 00 00 00 00 00 00 1F FD
Checksum
discrete input (discrete feedback) information (0)
- lowbyte-highbyte order
number of databytes (16)
function code 02 read discrete inputs (discrete
feedback)
slave address 200 in example
telegram example FC04 read data as input to master (word feedback)
Request
C8 04 02 00 00 08 E1 ED
Checksum
number of data high-, lowbyte
database address (decimal 512)
function code 04
slave address 200 in example
Response
C8 04 10 03 C4 00 0F 42 84 50 A0 00 00 00 00 00 00 00 00 99 41
Checksum
Reg. 0x208 discrete process inputs feedback
signals
Reg. 0x207 analog process input 2 feedback
high-, lowbyte (0)
Reg. 0x206 analog process input 1 feedback
high-, lowbyte (0)
Reg. 0x205 torque feedback high-, lowbyte (0)
Reg. 0x204 various discrete feedback signals
Reg. 0x203 various discrete feedback signals
Reg. 0x202 various discrete feedback signals
Reg. 0x201 position feedback high-, lowbyte
(964)
number of databytes (16)
function code 04 read input registers
slave address 200 in example
It is important to pay attention to the fact that the address count in the telegrams is starting at zero
and the coil and register address counts are starting at one, thus resulting in an address offset of
one!

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 8 of 18
Prepared by: Ste
2.3.2 Accesses for master output data ( actuator command signals)
Register
Bit
Coil
Signal
Meaning
0x201 0..7 1..8 Reference value low byte Reference value 0...1000 ppt
8..15 9..16 Reference value high byte
0x202 0 17 Automatic mode Activates the integral 3-point position
controller
1 18 Stop Stops the drive when automatic = 0
2 19 Close Moves the drive to CLOSED when
automatic = 0
3 20 Open Moves the drive to OPEN when automatic
= 0
4 21 Emergency travel (ESD) Activates the emergency travel of the drive
5 22 Pulse operation active Activates pulse operation when set to
external
6 23 Enable local control Local control on station is enabled
7 24 Channel select Channel switch over on 0 to 1 transition
8 25 Fault Acknowledge Reset mechanism for dedicated stored
faults (e.g. torque, phase errors) as
described in actuator operation manual -
valid for software revisions greater or equal
V01.05.0048
9..15 26..32 unused unused
0x203..
0x220
33..512
In order to access the command signals, the function codes FC 05 (Force Single Coil) or FC 06 (Preset Single
Register) are recommended to be used. The function codes FC 15 (Force Multiple Coils) and FC 16 (Preset
Multiple Registers) are also supported. The following tables give telegram examples for FC05 and FC06
function codes.
telegram example FC05 write single bit of master output data (command OPEN)
Request
C8 05 00 13 FF 00 6C 66
Checksum
value of coil (command set - TRUE)
database address (Coil 20 - command OPEN)
function code 05 write single coil (discrete command - OPEN)
slave address 200 in example
Response
C8 05 00 13 FF 00 6C 66
Checksum
value of coil (command set - TRUE)
database address (Coil 20 - command OPEN)
function code 05 write single coil (discrete command - OPEN)
slave address 200 in example
telegram example FC06 write single data of master output (setpoint value to 50
0)
Request
C8 06 02 00 01 F4 99 FC
Checksum
data value high- lowbyte as integer (setoint 500)
database address (decimal 512)
function code 06 write single register (commands as integer)
slave address 200 in example
Response
C8 06 02 00 01 F4 99 FC
Checksum
data value high- lowbyte as integer (setoint 500)

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 9 of 18
Prepared by: Ste
database address (decimal 512)
function code 06 write single register (commands as integer)
slave address 200 in example
The actuator commands can also be read back for checking purposes with the function codes FC 01 (Read
Coil Status) or FC 03 (Read Holding Registers). The following tables give telegram examples for these
function codes.
telegram example FC01 read single bit of master output data (command check)
Request
C8 01 00 00 00 80 2C 33
Checksum
number coils (discrete command bits - 128)
database address (decimal 0)
function code 01 read coil status (command check)
slave address 200 in example
Response
C8 01 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 A6 6D
Checksum
discrete coil (command
check) information (0) -
lowbyte-highbyte order
number of databytes
function code 01 read coil
status (command check)
slave address 200 in
example
telegram example FC03 read back of master output as integer (command check)
request
C8 03 02 00 00 08 54 2D
Checksum
number of data (commands packed as integer - 8)
database address (decimal 512)
function code 03 read holding register (command check as integer)
slave address 200 in example
Response
C8 03 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 07 D5
Checksum
holding register values
(command check as integer,
highbyte-lowbyte order)
number of databytes
function code 03 read holding
register (command check)
slave address 200 in
example
It is important to pay attention to the fact that the address count in the telegrams is starting at zero
and the coil and register address counts are starting at one, thus resulting in an address offset of
one!

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 10 of 18
Prepared by: Ste
2.4 Parameterisation
The modbus relevant settings can be changed menu driven using the local control unit. The
parameters are to be found in the menu tree under Menu\Parameters\Interface\Modbus.
2.4.1 Communication settings – addresses, baud rate, parity
The slave address can be set in the range between 1 and 247. In case of redundancy, the
address has to be set for both channels. The baud rate settings are done by a selection of
the required and available value out of a lookup table. The parity can be set to even, odd or
none. The number of stop-bits are set automatically according to the selected parity setting.
2.4.2 Number of channels – bus profile
The actuator can be ordered with a redundant modbus channel. In this case, the parameter
bus profile is set to redundant by the manufacturer, otherwise to standard.
2.4.3 Redundancy modes – line redundant vs. master redundant
In case of a redundant interface card, it is possible to set up two different redundancy
modes. The different modes have a different reply behaviour.
For line redundant mode, it is possible to block the reply of the inactive channel by setting
the parameter redundancy reply to “Active channel”. This is necessary, if both channels use
the same bus line with the same address setting.
In master redundant mode, the parameter has to be set to “both channels”.
For both modes, the behaviour of channel select and switch over is the same. On start-up,
the actuator selects the first valid channel as active channel. If the communication on this
channel fails, the actuator switches to the other channel after the timeout is expired – for
description of timeout settings see description of fail-safe.
Only if none of the channels is valid, the fail-safe mechanism becomes active (if activated).
An active switchover to the other channel can be forced by setting a high to low transition
on the special bit in the cyclic data stream.
2.4.4 Function Fail-Safe – Timeout setting
Once a bus communication was established, a fail-safe mode is available if the actuator is
in remote mode. This fail-safe mode becomes active, if the communication is no longer
active, and the set timeout is exhausted. The timeout value can be set in units of

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 11 of 18
Prepared by: Ste
0.1seconds in the range from 1 to 255 (0.1 to 25.5 seconds). In case of fail-safe the
actuator action can be parameterised as explained in the i-Matic instruction manual.
2.4.5 Fault messages
Fault messages can be reset depending on the active fault by :
- a movement command in opposite direction in case of a torque fault
- a new movement command in case of direction monitoring
- directly if the fault is no longer existing in all other cases

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 12 of 18
Prepared by: Ste
2.5 Electrical connection
2.5.1 Actuators i-Matic for normal operation – DiM-X0X
2.5.1.1 Compact plug assembly
The electrical connection is done on the wiring board DiM-19 which is assembled on a
mounting plate in the compact plug housing. As an example for explanation, the cable
assembly for i-Matic with redundant field bus and optional two analogue and four digital
process inputs as inner parts of the compact plug is given below.
(1)
Optional: external 24 VDC supply of i-Matic unit (input) with tolerance +10%, -5%
and less than 500mA load.
Optional: auxiliary 24 VDC supply (output) for external use allows 60mA load.
Mounting plate for power connector
and wiring board (backside view)
Power connector wire size 0.5 to 2.5
mm². Standard: cage clamp
Optional: screwing terminals
Various screwing terminals
depending on ordered options:
terminal size: AWG 16..26
solid wire: 0.14 to 1.5 mm²
flexible wire: 0.14 to 1 mm²
Two optional analogue inputs
Four optional digital inputs
Channel 2 incoming and outgoing
RTS signals
Optional 24V external power
(1)
Channel 1 incoming and outgoing
Strain relieves incoming, outgoing bus and
optional process inputs are independently
switchable to ground (switches on the front
side)

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 13 of 18
Prepared by: Ste
Insight view on DREHMO i-Matic compact plug
The wiring of the bus lines A(-), B(+), has to be done according to the given labels on the
corresponding terminals. Cables coming from the master have to be connected on the input
terminals (labeled IN) and the cables going to the end of the segment have to be wired to
the output terminals (labeled OUT). The connection of the shielding for incoming or
outgoing cables has to be done in the same manner.
Mounting plate with electric assembly
(front side view)
Power connector
Control connector
Compact plug housing
Wiring board
Slide switches for bus termi
nation
Slide switches for shield grounding
O
-
ring seal
Dual cable conduits with metric
(standard) winding for cable
glands:
M 32 x 1.5 mm (standard)
PG 29 (optional)
Device is shipped with blind plugs
Single cable conduit with metric
(standard) winding for cable gland:
M 20 x 1.5 mm (standard)
PG 13.5 (optional)
Device is shipped with blind plugs

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 14 of 18
Prepared by: Ste
2.5.1.2 Bus termination
The termination of the bus line can be done individually for the channels 1, 2 by setting the
slide switches S3, S4 on the connection board DiM-19 in the compact plug. If the
termination on one of the channels is activated, the outgoing line of this channel is
disconnected from the master.
example for termination with slide switch S3, S4 on DiM-19 connection board
- channel 1 without termination – bus connection forward to next device
- channel 2 termination activated – last device on bus segment
2.5.1.3 Grounding of the cables´ shields in case of copper cable use
To avoid high currents on the cables´ shields in systems with very different earth potentials,
the shields of the cables connected to the inputs and those connected to the outputs can be
grounded directly, or using a combination of resistor and capacitor using the grounding
switches ( see 2.5.1.1) on the connection board. The resistor reduces DC-currents,
whereas the capacitor has a low impedance for fast changes between ground potentials.
High impedance grounding of shield

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 15 of 18
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2.5.1.4 Interface with fibre optic connection
Actuators for ordinary surroundings (Non EX) may have an extended compact plug to incorporate a special
fibre optic interface board. The connection of the fibre optic cables to the interface board is shown in the
following picture:
Fibre optic connection inside the compact plug
The connector for the fibre optic wires is the one of type F-St. The core of the optical fibres might be of
diameter 50µm or 62.5 µm. To connect the fibre optic cables, open the cover of the extended compact plug.
Using the maximum of four cable glands (M20x1.5) the cables can be inducted into the housing. Connect the
optical fibres to the appropriate plugs: Connect the output of a device with the input of the other one and the
input with the output. The board provides an active connection between inputs and outputs. By default the
converter board is powered by the electronic unit. Thus in case of a power failure the communication to the
rest of the slaves connected to the output of the device is lost. This effect can be avoided by additionally
powering the electronic unit with external 24 V DC

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 16 of 18
Prepared by: Ste
2.5.2 Actuator i-Matic for Ex-Zone acc. ATEX device category 2 G – DiM-X1X
2.5.2.1 Connection with copper cable
The connection of the modbus signal lines (A, B) from inputs and outputs have to be done on the appropriate
terminals in the termination compartment. If the actuator is not the last node on the bus, the necessary T-
piece may be made up by means of using the available double terminals (A1, B1, A2, B2) which are
electrically connected. A bridge between incoming and outgoing bus signals has to be made to achieve the
required T-piece.
The bus terminator always has to be provided near or downstream of the last bus device for correct bus
termination. If the last bus device is an i-Matic type DREHMO actuator, the terminator can be activated by
connecting terminals Tx+ with Bx and Tx- with Ax (see next picture), (x = number of channel).
-Connection of two Profibus systems to an i-Matic drive
-channel 1: leading to the next device
-channel 2: last device on the segment (terminator activated)
Devices for use in explosive areas have a spur length of approximately 40 cm for each channel.

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 17 of 18
Prepared by: Ste
2.5.2.2 Connection with fibre optic cable
Devices of category 2 G/D for explosive areas have the connection solely by rail mounted screw terminals.
The fibre optic converter
4)
inside the extended safety compartment is powered by the electronic unit. The
converter is pressure proof sealed, and the optical interface is intrinsically safe. Actuators can be fitted with
single line fibre optic interfaces (e.g. line or star structure), or with a redundant fibre optic interface for a ring
structure. The breakout has to be put inside the compartment. It is therefore important to keep the size of the
breakout small enough to be able to push it through a cable gland of the size M20. The standard connector is
of type F-SMA. The following pictures show the inside of the wiring compartment.
- Connection with fibre optic interface – terminals - Connection with fibre optic interface – fibre optic cable
2.5.2.2.1 Setting of transmission power
The converter board has two switches S1 and S2. The switches can be used to set the transmission power
according to the requirements of the input and output independently. If the adjacent devices are only a short
distance apart, the appropriate switch should be switched to „-“ (default setting). If the transmission power is
not sufficient to cover the distance between two devices, the switch can be set to position „+“.
The two LEDs on the board show whether the power supply is OK (green LED), and whether data are
transferred via the optical PROFIBUS (yellow LED).

Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12 Page 18 of 18
Prepared by: Ste
2.6 Interface to external sensor - process inputs
Actuators of type i-Matic can be equipped with an optional interface for an external sensor.
The interface consists of four discrete inputs (24 V DC), and two analogue inputs
(4...20mA). The discrete inputs with common ground are galvanically isolated from the
electronic potential by optocouplers. The nominal current of the discrete inputs is 12 mA for
an input voltage of 24 V DC. The following picture shows the structure of the discrete
inputs.
- digital process inputs
The analogue inputs are connected to the electronic potential. The following pictures show
examples of how to use these inputs:
- connection with two wires - connection with three wires - connection with four wires
DREHMO GmbH
Zum Eichstruck 10
57482 Wenden/Germany
Fon: [phone]
Fax: [phone]
Internet:www.drehmo.com
eMail: [e-mail]