EP0624832A2 - Electronic control system for modular structured valve station - Google Patents

Abstract

An electronic control system for a valve station of modular construction is proposed, which has a fluid distributor arrangement equipped with electrically controllable valves (19-26), the valves (19-26) being driven via at least one control module (17, 18). Furthermore, input and/or output modules (14-16) and a central electronic control unit (10) are provided, to which the individual modules (14-18) are connected for control and/or for data communication. The control unit (10) is connected to the modules (14-18) via a bus line system (28), and each module (14-18) has a programmable address decoder (29-33), means being provided for the sequential configuration of the modules (14-18) and for the automatic allocation of individual addresses for the individual modules (14-18). By this means, the valve station can be constructed or expanded in any desired way, the modules connected being automatically recognised and provided with addresses. <IMAGE>

Description

The invention relates to an electronic control device for a modular valve station, which has a fluid distributor arrangement equipped with electrically controllable valves, the valves being controlled via at least one control module, with input and / or output modules and with a central electronic control unit to which the individual Modules for control and / or for data communication are connected.

Control devices of this type have been marketed by the applicant for a long time under the name "valve islands" or "installation islands", with essentially a one-piece or multi-piece plate-like fluid distributor being equipped with multi-way valves. In addition, such a modular valve station also have input / output modules for receiving sensor signals or for controlling further external devices. The central control unit controls the various modules via a bus line system. Such an electronic control device or valve station is also known, for example, from DE-GM 92 11 109.

In a known manner, in such devices each module has an address decoder which compares a fixed address of the respective module with the address currently appearing on the address bus. A controlling microprocessor of the central control unit can only access this module if it is identical. The addresses are usually set using switches or fixed wiring. When compiling such a known valve station, the addresses must therefore be set for each module and brought into line with the programming of the central control unit. This is very time-consuming and cumbersome, in particular when the valve station is expanded by additional modules, for example when additional sensors are installed, additional external devices are to be controlled or additional additional valves are to be actuated.

It is therefore an object of the present invention to simplify the addressing of modules in a valve station.

This object is achieved in that the control unit is connected to the modules via a bus line system, that each module has a programmable address decoder and that means are provided for sequential configuration of the modules and for the automatic assignment of individual addresses for the individual modules.

The device according to the invention allows a highly flexible, automatic address assignment without any manual settings being required. The automatic address assignment remains effective even if the valve station is expanded by additional modules, and the electronic control unit automatically assigns additional addresses.

Advantageous further developments and improvements of the control device specified in claim 1 are possible through the measures listed in the subclaims.

The address decoders have, in particular, read / write memories for storing the assigned addresses. The currently valid address can be read into this from the central control unit.

Advantageously, active means are provided in a configuration phase for sequential switching of the access to the individual address decoders by the control unit, an address or an address mask being stored in the respective address decoder during the access. As a result, the individual address decoders are successively provided with addresses, or existing addresses are overwritten with new addresses. The addresses to be stored are fed to the address decoders via an address bus. Programming is therefore carried out without the use of data lines, since the data are transferred via the address lines.

The configuration phase is expediently designed as an initialization phase. Means are provided for querying and identifying the respective module during the access phase, with corresponding individual module identification data being able to be transmitted to the control unit via a data bus. This takes place before the address assignment a system configuration recognition which is also carried out automatically. The transmitted module identification data are linked in the control unit with the address assigned to the corresponding module.

Furthermore, means for automatically switching to a work phase after the configuration phase has been carried out are advantageously provided. The configuration phase itself is triggered by write access to an address reserved for it.

An address decoder can be assigned to each valve in the valve station, but it is also possible for several valves to be assigned to an address decoder which is provided with an address mask and a corresponding number of addresses.

To control the passage of input and / or output signals in the respective modules, control outputs of the address decoders are connected to electronic switches which control these input and / or output signals and which can be designed, for example, as buffers or flip-flops.

The central control unit can advantageously also be designed as a fieldbus station and work in a network with other fieldbus stations or also autonomously.

An expedient, easily assembled and expandable mechanical arrangement consists in that a variable number of modules can be attached to the central control unit, preferably in a row arrangement consisting of at least one row. As a result, any further modules can be added to such a row, an address being automatically assigned in the next configuration or initialization phase.

Fig. 1

eine schematische Gesamtansicht einer Ventilstation mit Ventilmoduln sowie Eingangs- und Ausgangsmoduln,

Fig. 2

ein Schaltbild eines Ventilmoduls,

Fig. 3

ein Schaltbild eines Ausgangsmoduls und

Fig. 4

ein Schaltbild eines Eingangsmoduls.

Embodiments of the invention are shown in the drawing and explained in more detail in the following description. Show it:

Fig. 1

a schematic overall view of a valve station with valve modules and input and output modules,

Fig. 2

a circuit diagram of a valve module,

Fig. 3

a circuit diagram of an output module and

Fig. 4

a circuit diagram of an input module.

In the exemplary embodiment of a valve station shown in FIG. 1, a central electronic control unit 10 is designed as a fieldbus station in a manner known from the prior art mentioned at the beginning and is connected to a usually two-wire fieldbus 11. Several such control units 10 or valve stations can be connected to this fieldbus 11, which is indicated by a dashed continuation of the fieldbus 11. A central computer 12 connected to the fieldbus 11 can control the individual control units 10 as a master station, or this central computer 12 merely transfers the control program to the control unit 10, which can then autonomously control the valve station. In this case, a display and / or control device can then also be connected to an interface 13 of the control unit 10. Another possibility is that if there are several valve terminals connected via the fieldbus 11, a control unit 10 works as a master unit, to which the other control units are subordinate.

At this control unit 10, three input and / or output modules 14-16 are arranged in a row arrangement on one side, which modules are not shown in detail, for example Are screwed together. On the opposite side, two valve modules 17, 18 are connected to the control unit 10 in a row arrangement, each of which carries four valves 19-22 and 23-26, respectively. Such a valve module consists, in a manner known per se and not shown in detail, of a fluid distributor for a pneumatic or hydraulic medium, which has feed and ventilation channels running inside. In the illustrated embodiment, the four valves 19-22 and 23-26 are mounted on this fluid distributor, which communicate with the channels of the fluid distributor via branch channels. Connection means provided on the valves allow the connection of pressure medium lines, which lead to working means which can be actuated by pressure medium and which are also not shown. Each valve 19-26 has an electrically actuable valve drive.

The control unit 10 has as a central program-controlled device a microprocessor 27 which is connected via a bus line system 28 to programmable address decoders 29-33 in the modules 14-18. In the case of the input and / or output modules 14-16, these address decoders 29-31 control the passage of input or output signals to input or output connections 34-36. With the valve modules 17, 18 these address decoders 32, 33 control the individual valves 19-26.

When the individual modules 14-18 are plugged together, the bus line connections are automatically established by appropriate plug devices, for example by boards running transversely through the modules, which are formed at their ends as plugs or couplings. With the valve modules 17, 18, the fluidic connections between the individual fluid distributors are simultaneously established.

In deviation from the exemplary embodiment shown, it is of course also possible in principle to provide a single, continuous fluid distributor on which valve modules are assembled, which only contain the valves, the valve controls and the address decoder. Another possibility is to assign a larger number of valves to a single address decoder or, for example, to assign a separate address decoder to each valve. In the former case, for example, a single address decoder could control all valves.

The entire valve terminal can of course also work completely independently, that is, the control unit 10 is designed as an independent control unit and not with a field bus or the like. connected.

2 shows the valve module 17 with regard to its electronic circuit as an exemplary embodiment. The valve station internal bus line system 28 consists of a data bus 37 containing eight data lines BD 0 - BD 7, an address bus 38 containing fifteen address lines A0 - A14, control lines 39, 40 (RDNOUT and WRNOUT) and a so-called daisy chain connection 41 (DCI / DCO ). All of these lines are connected to the address decoder 32. The structure of such an address decoder corresponds in principle to the known, non-programmable address decodes, with the exception that an internal read / write memory (not shown) is additionally provided here, into which addresses can be read in via the address bus 37. Furthermore, a comparator, also not shown, is provided, which compares the stored address with the address present on the address bus 37 in work mode and, if the addresses match, a control signal on an output line 42 gives. Furthermore, this address decoder 32 contains individual module identification data which can be applied to the data bus 37 via corresponding lines 43. This can be, for example, a permanently connected data word.

The output line 42 is connected to an enable input G of a decoder 44, for which, for example, the commercially available component HC 239 can be used. This decoder 44 is connected to the address bus 38 via two address lines 45. Control outputs of this decoder 44 control four D flip-flops 46-49, which perform a switch function in control lines 50-53, which connect the data bus 37 to electrical valve drives of the valves 19-22. The number of D flip-flops 46-49, the control lines 50-53 and the address lines 45 naturally depends on the number of valves to be controlled.

The mode of operation of the entire self-configuring system is described below. After the operating voltage has been switched on, the operating system of the microprocessor 27 starts with a configuration or initialization phase. The line DCI of the daisy chain connection 41 is in the first module, for example in the valve module 17, if this is connected as the first module in the daisy chain connection 41, connected to the system reset of the microprocessor 27. This line is set to zero for a short time. If DCI = 0, the DCO line of this module is also set to zero. This in turn leads to DCI = 0 for the next module, etc. This puts all connected modules in the basic state. After the reset time has expired, the line DCI of the first module, that is to say of the valve module 17, assumes state 1. All other DCO and DCI lines remain in state 0. Only with this signal combination (DCI = 1 and DCO = 0) can the module in question be accessed during the initialization phase.

The microprocessor 27 now generates a read access and at least one write access. The address decoder 32 has eight configuration outputs 43 with "open-drain" properties. The microprocessor now reads the identifier of the address decoder 32 or the valve module 17 via the lines 43 and the data bus 37. Here he recognizes what type of module it is, for example whether it is a module that only needs one address to control a single control line, or that to control several output lines multiple addresses needed. Now, in two write accesses, the microprocessor 27 assigns an address and an address mask to this identifier and transfers them via the address bus 38 to the internal memory of the address decoder 32. With WRN = 0, the module address to be programmed is changed from the address bus 38 into the memory of the address decoder which acts as an address register 32 adopted. In the valve module 17, an address mask is transmitted to the address decoder 32 via the address bus 38. This address mask determines the number of bytes that can be accessed in read mode as well as in write mode, starting from the base address. This specifies an active address area. After this second write access, the initialization of this module 17 is completed and the DCO line changes to a 1 signal. This means that the conditions DCI = 1 and DCO = 0 are fulfilled for the next module, and this can be initialized. This process is repeated until all modules have been identified and given an address. The initialization is then finished. The termination criterion for the initialization is fulfilled when all data lines are supplied with a 1 signal. A read access to a reserved address now switches to work mode. With write access to the reserved address, everyone can simultaneously Address decoder 29-33 can be switched back to the initialization mode.

In the working mode, all address decoders 29-33 work according to their previous programming during the initialization phase, that is, they can be addressed via the address range assigned to them. The software switchover between the initialization and working mode is carried out solely by the address (38), RDN (39) and WRN lines (40), which means that no special data or control lines are required for this. If an address corresponding to an assigned address in one of the address decoders is present on the address bus 38, this address decoder responds and generates logically linked output signals with the read signal (RDN) and / or write signal (WRN).

In the case of the address decoder 32, the decoder 44 is then enabled, which, depending on the address supplied via the address lines 45, enables one of its four outputs and responds with the corresponding output signal to one of the four D flip-flops 46-49 via the clock input. As a result, the signal present via the data bus 37 is transmitted to the output of the respective D flip-flop 46-49, and the corresponding valve 19-22 is activated.

3 shows the circuit of an output module, for example that of the output module 14, as an exemplary embodiment. Identical and identically acting components are provided with the same reference symbols and are not described again. The output line 42 is connected to the clock input of a single D flip-flop 54, the output of which is connected via an output amplifier 55 to the output connection 34, which can be designed, for example, as a socket or plug coupling. The mode of operation also largely corresponds to the exemplary embodiment shown in FIG. 2. If the address decoder 29 is addressed by the address assigned to it, the control signal on the data bus 37 is transmitted via its output line 42 through the D flip-flop 54 to the output connection 34 in order to control an external unit connected to it, for example an external hydraulic valve, an actuator, a motor or the like.

The circuit of the module shown in FIG. 3 can also be used to control valves 19-26 of the valve station if these are individually provided with address decoders.

4 shows an input module as an exemplary embodiment shown, for example the input module 15. Here, too, identical or identically acting components are provided with the same reference numerals and are not described again.

This input module 15 is used to supply external signals to the microprocessor 27, for example sensor signals, limit switch signals or the like. The external signal passes via the input connection 35 into a buffer 56, for which the commercially available component HC 244 can be used, for example. If the address decoder 30 is addressed, the signal is transmitted from the buffer 56 to the data bus 37 and from there to the microprocessor 27 by means of a signal on the output line 42.

If the input signal is present as an analog signal, an analog / digital converter must also be connected upstream, the digital data word formed being transferable to the data bus 37 via a buffer arrangement and a plurality of data lines. A plurality of buffers or a buffer arrangement with a plurality of lines are then controlled in parallel by the output line 42. Correspondingly, analog output signals could of course also be used in the arrangement according to FIG. 3 by means of a digital / analog converter are formed, to which a plurality of data lines of the data bus 37 are fed on the input side. Of course, combined input / output modules can also be implemented, as shown in FIG. 3 and controls input lines as shown in FIG. 4. This can be implemented via a correspondingly large address area of the address decoder.

Claims (10)

Electronic control device for a modular valve station, which has a fluid distributor arrangement equipped with electrically controllable valves, the valves being controlled via at least one control module, with input and / or output modules and with a central electronic control unit to which the individual modules for control and / or are connected for data communication, characterized in that the control unit (10) is connected to the modules (14-18) via a bus line system (28), that each module (14-18) has a programmable address decoder (29-33) and that means for sequentially configuring the modules (14-18) and for automatically assigning individual addresses for the individual modules (14-18) are provided. Control device according to Claim 1, characterized in that the address decoders (29-33) have read / write memories for storing the assigned addresses. Control device according to claim 1 or 2, characterized in that in a configuration phase, active means are provided for the sequential switching of the access to the individual address decoders (29-33) by the control unit (10), an address and / or address mask being shown during access the respective address decoders (29-33) are stored and the addresses to be stored can preferably be fed to the address decoders (29-33) via an address bus (38). Control device according to claim 3, characterized in that the configuration phase is designed as an initialization phase. Control device according to claim 3 or 4, characterized in that means for querying and identifying the respective module (14-18) are provided during the access phase, corresponding individual module identification data being able to be transmitted to the control unit (10) via a data bus (37), which can be linked in the control unit (10) in particular to the address assigned to the corresponding module (14-18). Control device according to one of Claims 3 to 5, characterized in that means for automatically switching over to a working phase after the configuration phase has been carried out are provided and / or that the configuration phase can be triggered by write access to an address reserved for this purpose. Control device according to one of the preceding claims, characterized in that each valve (19-26) is assigned to an address decoder or that several valves (19-22 or 23-26) are assigned to an address decoder (32 or 33) which is associated with a Address mask and / or a corresponding number of addresses is applied. Control device according to one of the preceding claims, characterized in that control outputs (42) of the address decoder (29-33) are connected to electrical switches (44-49, 54, 56) which control the passage of input and / or output signals. Control device according to one of the preceding claims, characterized in that the central control unit (10) is designed as a fieldbus station. Control device according to one of the preceding claims, characterized in that a variable number of preferably screwable modules (14-18) arranged in at least one row can be attached to the central control unit (10).

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