Title: Fieldbus connecting system for actuators or sensors
Abstract: A modular connecting system for connecting an external device to a fieldbus system includes a fieldbus-specific fieldbus interface circuit and a fieldbus-independent interface device connected to the interface circuit. The interface device has operating modes and is to be selectively connected to an external device including not only simple sensors or actuators with parallel signal transmission, but also complex sensors or actuators with series signal transmission. The interface device connects the external device to said interface circuit during parallel signal transmission and serial signal transmission. The interface device is programmed to autonomously check a type of the external device connected to said interface device and to select an appropriate subset of said operating modes for the type of the external device.
Patent Number: 6,889,282 Issued on 05/03/2005 to Schollenberger
| Inventors:
|
Schollenberger; Lothar (Hirschberg, DE)
|
| Assignee:
|
ABB Patent GmbH (Ladenburg, DE)
|
| Appl. No.:
|
891186 |
| Filed:
|
June 25, 2001 |
Foreign Application Priority Data
| Jun 23, 2000[DE] | 100 30 845 |
| Current U.S. Class: |
710/305; 700/1; 702/1; 710/8; 710/11; 710/104; 710/105; 713/1; 713/100 |
| Intern'l Class: |
G06F 013/14 |
| Field of Search: |
710/11,105,104,8,305
713/1,100
700/1
702/1
|
References Cited [Referenced By]
U.S. Patent Documents
| 5764891 | Jun., 1998 | Warrior.
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| 5841654 | Nov., 1998 | Verissimo et al.
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| 5923557 | Jul., 1999 | Eidson.
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| 6032203 | Feb., 2000 | Heidhues.
| |
| 6098116 | Aug., 2000 | Nixon et al.
| |
| 6128689 | Oct., 2000 | Hassbjer et al.
| |
| 6151640 | Nov., 2000 | Buda et al.
| |
| 6192281 | Feb., 2001 | Brown et al.
| |
| 6266726 | Jul., 2001 | Nixon et al.
| |
| 6304934 | Oct., 2001 | Pimenta et al.
| |
| Foreign Patent Documents |
| 43 02 032 | Aug., 1994 | DE.
| |
| 43 44 904 | Aug., 1995 | DE.
| |
| 196 46 219 | Dec., 1997 | DE.
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| 29810482 | Oct., 1999 | DE.
| |
| 0 680 421 | Nov., 1995 | EP.
| |
| 895145 | Feb., 1999 | EP.
| |
| 0 906 595 | Apr., 1999 | EP.
| |
| WO 9937435 | Jul., 1999 | WO.
| |
Other References
Lee, Kang, "IEEE 1451: A Standard in Support of Smart Transducer Networking,"
May 4, 2000, IEEE, Instrumentation and Measurement Technology Conference, 2000,
vol. 2, p. 525-528.*
Santori, M., et al., "Fieldbus Brings Protocol to Process Control," Mar. 1996,
IEEE, Spectrum, vol. 33, Issue 3, p. 60-64.*
Wilson, P.D., et al., "Applications of a Universal Sensor Interface Chip (USIC)
for Intelligent Sensor Applications," Dec. 7, 1995 IEEE Colloquium on Advances
in Sensors, p. 3/1-3/6.
|
Primary Examiner: Rinehart; Mark H.
Assistant Examiner: Mason; Donna K.
Attorney, Agent or Firm: Greenberg; Laurence A., Stemer; Werner H., Mayback; Gregory L.
Claims
1. A modular connecting system for connecting an external device to a fieldbus
system, comprising:
a fieldbus-specific fieldbus interface circuit;
a fieldbus-independent interface device connected to said interface circuit;
said interface device having operating modes and to be selectively connected
to an external device including at least one:
sensor having a varying degree of complexity; and
actuator having a varying degree of complexity;
said interface device connecting the external device to said interface circuit
during parallel signal transmission and serial signal transmission; and
said interface device programmed to autonomously check a type of the external
device connected to said interface device and to select an appropriate subset of
said operating modes for the type of the external device.
2. The connecting system according to claim 1, wherein:
said operating modes include a first operating mode and a second operating mode;
and
said interface device has an electronic circuit programmed to set up said interface
device by selecting one of said first operating mode and said second operating
mode.
3. The connecting system according to claim 2, wherein said electronic circuit
is a microcontroller.
4. The connecting system according to claim 2, wherein:
said operating modes include:
a first operating mode for parallel signal input; and
a second operating mode for serial signal input;
said interface device receives an operating voltage;
said interface device is programmed:
to operate in said second operating mode when the operating voltage is switched
on;
to send a serial test message to the external device connected to said interface
device and to wait for a response from the external device; and
to switch to said first operating mode if the response is not received by said
interface device.
5. The connecting system according to claim 1, including a fieldbus plug-in apparatus,
said interface device being integrated in said fieldbus plug-in apparatus.
6. The connecting system according to claim 1, wherein said interface device
is programmed to output a serial output signal in all of said operating modes.
7. The connecting system according to claim 1, wherein said interface device
directly connects to the external device by a standard plug-in apparatus having
a standardized connector wiring.
8. The connecting system according to claim 1, including a standard plug-in apparatus
having a standardized connector wiring, said interface device directly connecting
to the external device by said standard plug-in apparatus.
9. A modular connecting system for connecting an external device to at least
one fieldbus cable of a fieldbus system, the connecting system comprising:
a fieldbus plug to be removably connected to the at least one fieldbus cable;
said fieldbus plug having:
a fieldbus-specific fieldbus interface circuit to be connected to at least one
fieldbus cable; and
a fieldbus-independent interface device connected to said interface circuit;
said interface device having operating modes and to be selectively connected
to an external device;
said interface device connecting the external device to said interface circuit
during parallel signal transmission and serial signal transmission; and
said interface device programmed to autonomously check a type of the external
device connected to said interface device and to select an appropriate subset of
said operating modes for the type of the external device.
10. In a fieldbus system having at least one fieldbus-specific fieldbus interface
circuit, a modular connecting system for connecting an external device to the fieldbus
system, the connecting system comprising:
a fieldbus-independent interface device connected to the interface circuit;
said interface device having operating modes and to be selectively connected
to the external device;
said interface device connecting the external device to the interface circuit
during parallel signal transmission and serial signal transmission; and
said interface device programmed to autonomously check a type of the external
device connected to said interface device and to select an appropriate subset of
said operating modes for the type of the external device.
11. A modular connecting system for a fieldbus system, comprising:
a fieldbus-specific fieldbus interface circuit;
a fieldbus-independent interface device connected to said interface circuit;
sensors having types and varying degrees of complexity;
actuators having types varying degrees of complexity;
said interface device having operating modes and selectively connected to one
of said sensors and said actuators;
said interface device connecting said one of said sensors and said actuators
to said interface circuit during parallel signal transmission and serial signal
transmission; and
said interface device programmed to autonomously check a type of said one of
said sensors and said actuators connected to said interface device and to select
an appropriate subset of said operating modes for said type of said sensors and
said actuators.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a connecting system for connecting sensors or actuators
to a fieldbus.
In automation systems, fieldbuses are used for connecting sensors or actuators
to input/output apparatuses of control and regulation devices. A large number of
different fieldbuses are commercially available and, as a consequence, there are
a correspondingly large number of fieldbus-specific fieldbus interface circuits
to which actuators or sensors can be connected.
Sensors are used in automation systems for detecting process variables. A
wide range of sensor types are used that, in the simplest case, supply only a binary
signal, but that can also supply a number of digital or analogue signals. The wide
range of actuators is similar, and these may be simple switching devices or else,
for example, frequency converters with control functions.
Users of sensors or actuators desire to be able to use such products universally,
that is to say, to allow them to be connected to any desired fieldbus, or for them
at least to be available in a different configuration for connection to different
fieldbuses. For universal applicability, a configuration having a number of fieldbus
interface circuits would be required in sensors or actuators. Such a configuration
is impossible for cost and space reasons. The provision of sensors or actuators
with different fieldbus connections would involve considerable effort for the supplier.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide a fieldbus connecting
system for actuators or sensors that overcomes the hereinafore-mentioned disadvantages
of the heretofore-known devices of this general type and that specifies a system
for connecting sensors or actuators of different complexity to different fieldbus
systems that can be produced with relatively little additional effort.
With the foregoing and other objects in view, there is provided, in accordance
with the invention, a modular connecting system for connecting an external device
to a fieldbus system, including a fieldbus-specific fieldbus interface circuit
and a fieldbus-independent interface device connected to the interface circuit.
The interface device has operating modes and is to be selectively connected to
an external device including sensor and/or actuators having varying degrees of
complexity. The interface device connects the external device to the interface
circuit during parallel signal transmission and serial signal transmission. The
interface device is programmed to autonomously check a type of the external device
connected to the interface device and to select an appropriate subset of the operating
modes for the type of the external device.
In the connecting system for connection of sensors or actuators to a fieldbus
interface circuit of a respective fieldbus system according to the invention, the
fieldbus interface circuit has an upstream interface device, to which simple or
complex sensors or actuators can optionally be connected. The interface device
is set up to check autonomously what type of sensor or actuator is connected, and
to select an appropriate operating mode for it. The check is carried out by a test
message that the interface device sends to the connected actuator or sensor.
As a linking element, the interface device thus allows both simple and complex
standardized sensors or actuators to be connected to different, likewise standardized,
bus interface circuits.
In accordance with another feature of the invention, the operating modes include
a first operating mode and a second operating mode, and the interface device has
an electronic circuit programmed to set up the interface device by selecting one
of the first and second operating modes.
In accordance with a further feature of the invention, the electronic circuit
is a microcontroller.
In accordance with an added feature of the invention, the operating modes include
a first operating mode for parallel signal input, and a second operating mode for
serial signal input, the interface device receives an operating voltage, and the
interface device is programmed to operate in the second operating mode when the
operating voltage is switched on, to send a serial test message to the external
device connected to the interface device and to wait for a response from the external
device, and to switch to the first operating mode if the response is not received
by the interface device.
In accordance with an additional feature of the invention, there is provided a
fieldbus plug-in apparatus and the interface device is integrated in the fieldbus
plug-in apparatus.
In accordance with yet another feature of the invention, the interface device
is programmed to output a serial output signal in all of the operating modes.
In accordance with yet a further feature of the invention, the interface device
directly connects to the external device by a standard plug-in apparatus having
a standardized connector wiring.
In accordance with yet an added feature of the invention, there is provided a
standard plug-in apparatus having a standardized connector wiring, and the interface
device directly connects to the external device by the standard plug-in apparatus.
With the objects of the invention in view, there is also provided a modular
connecting system for connecting an external device to at least one fieldbus cable
of a fieldbus system, the connecting system including a fieldbus plug to be removably
connected to the a fieldbus cable. The fieldbus plug has a fieldbus-specific fieldbus
interface circuit to be connected to a fieldbus cable, and a fieldbus-independent
interface device connected to the interface circuit. The interface device has operating
modes and is to be selectively connected to an external device. The interface device
connects the external device to the interface circuit during parallel signal transmission
and serial signal transmission.
The interface device is programmed to autonomously check a type of the external
device connected to the interface device and to select an appropriate subset of
the operating modes for the type of the external device.
With the objects of the invention in view, in a fieldbus system having at least
one fieldbus-specific fieldbus interface circuit, there is also provided a modular
connecting system for connecting an external device to the fieldbus system, the
connecting system including a fieldbus-independent interface device connected to
the interface circuit. The interface device has operating modes and is to be selectively
connected to the external device. The interface device connects the external device
to the interface circuit during parallel signal transmission and serial signal
transmission. The interface device is programmed to autonomously check a type of
the external device connected to the interface device and to select an appropriate
subset of the operating modes for the type of the external device.
With the objects of the invention in view, there is also provided a modular
connecting system for a fieldbus system, including a fieldbus-specific fieldbus
interface circuit, a fieldbus-independent interface device connected to the interface
circuit, and sensors and actuators having types and varying degrees of complexity.
The interface device has operating modes and is selectively connected to a sensor
or actuator. The interface device connects the sensor or actuator to the interface
circuit during parallel signal transmission and serial signal transmission. The
interface device is programmed to autonomously check a type of the one of the sensors
and the actuators connected to the interface device and to select an appropriate
subset of the operating modes for the type of the sensors and the actuators.
Other features that are considered as characteristic for the invention are
set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in
a fieldbus connecting system for actuators or sensors, it is, nevertheless, not
intended to be limited to the details shown because various modifications and structural
changes may be made therein without departing from the spirit of the invention
and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together
with additional objects and advantages thereof, will be best understood from the
following description of specific embodiments when read in connection with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block circuit diagram of an interface configuration according to
the invention; and
FIG. 2 shows an embodiment of the configuration of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In all the figures of the drawing, sub-features and integral parts that correspond
to one another bear the same reference symbol in each case.
Referring now to the figures of the drawings in detail and first, particularly
to FIG. 1 thereof, there is shown a block circuit diagram of an interface device
34 in which a defined neutral interface, that is to say, an interface that
is independent of the respective fieldbus system, is implemented using an electronic
circuit, for example, a microprocessor or microcontroller. The interface device
34 is upstream of a fieldbus-specific fieldbus interface circuit
30,
to which lines of a fieldbus
31 can be connected. Both simple sensors
1
or actuators
2 as well as complex sensors
10 or actuators
20
can optionally be connected to the interface device
34. The method of operation
of such a configuration will be explained in the following text, with reference
to FIG.
2.
FIG. 2 shows an example configuration, in which a fieldbus plug-in apparatus
40 is used. The fieldbus plug-in apparatus
40 contains electronic
devices for providing a fieldbus interface circuit
30, to which two fieldbus
cables of a fieldbus
31 can be connected, and for providing a fieldbus independent
interface device
34. The fieldbus plug-in apparatus
40 also has a
five-pole standard plug-in apparatus
4, to which a sensor
1 or
10,
or an actuator
2 or
20, can optionally be connected.
The interface device
34 is set up to operate optionally in two operating
modes; namely, in a first operating mode that is referred to as Mode
1 and
in a second operating mode that is referred to as Mode
2. In Mode
1,
two digital signals can be read and one digital signal can be output in a parallel
mode. In Mode
2, signals can be input and output in a serial mode. The interface
device
34 is also set up to select the appropriate operating mode autonomously,
once an actuator or a sensor has been connected. To autonomously select the mode,
once the interface device
34 has been switched on, the interface device
34 first sends a serial test message in Mode
2 to the connected appliance
1,
2,
10, or
20, and waits for a response message.
If no such response arrives, the interface device
34 changes to Mode
1.
The illustration in FIG. 2 shows that, for example, a simple sensor
1 causes
Mode
1 to be selected, and a complex actuator
20 causes Mode
2
to be selected. The respectively appropriate signals are, therefore, applied to
the plug connections, these being defined in Standards. In principle, it is possible
to set up the interface device to distinguish between more than two operating modes,
depending on the response to the transmitted test message.
A major advantage provided by the invention is that the standard plug connection
4 that is provided on the fieldbus plug-in apparatus
40, in conjunction
with the automated selection of Mode
1, allows direct connection, for example,
of inductive proximity switches in a plug-in configuration as sensors, whose connection
sequence and connector wiring are standardized. Simple switching devices or switchgear
combinations likewise use Mode
1. Mode
2 is used for actuators and
sensors having a wider range of signals in which, in addition to simple binary
signals, digitized analogue values or parameters can also be transmitted.
*
