Control device and method for switching input/output units of a controller

Abstract

The invention relates to a controller (1) comprising a control unit (2), which communicates with at least one input and/or output unit (10) via a data transmission channel (3, 6) for exchange of process data (P). The controller (1) has predetermined power saving process data (V) for power-saving states (En), which are associated with the input/output units (10), and is designed to access the predetermined power-saving process data (V) instead the exchanged process data (P) when in the power saving state.

Claims

1. Controller comprising a control unit which communicates with at least one input and/or output unit via a data transmission channel for exchange of process data, wherein the controller has predetermined power-saving process data for power-saving states of the input/output units assigned to the input/output units, and is adapted to access the predetermined power-saving process data instead of the exchanged process data when being in the power-saving state, wherein the predetermined power-saving process data are assigned to individual channels of the at least one input and/or output unit, and wherein the control unit is adapted, by means of the power-saving process data, to switch selected channels, with bus members connected thereto, of the input/output units into a power-saving state, by accessing the assigned predetermined power-saving process data for the selected channel instead of using process data of the respective channel in order to switch the input/output units and the bus members into a power-saving state, wherein by defining power-saving profiles for individual channels particular bus members can be transferred into power-saving states without knowledge of the particular bus members, and the switchover into the power-saving state for selected input/output units and their channels is carried out by activation of a predetermined power-saving profile.

2. Controller according to claim 1, wherein the controller is adapted to switch groups of input/output units or groups of channels of input/output units for access to the predetermined power-saving process data into a power-saving state.

3. Controller according to claim 1, wherein the input/output units comprise a memory unit for storing the power-saving process data predetermined for the input/output units.

4. Controller according to claim 1, wherein the control unit comprises a memory unit for storing the predetermined power-saving process data assigned to the connected input/output units.

5. Controller according to claim 1, wherein the input/output units are connected to the control unit via a field bus controller or field bus coupler, wherein the field bus controller or field bus coupler comprises a memory unit for storing a process image for the process data to be exchanged and for the storing of the predetermined power-saving process data assigned to the connected input/output units.

6. A method for switching input and/or output units of a controller into a power-saving state of the input/output units, in which the power consumption of bus members, which are connectable to the input/output units, is reduced, the method comprising: storing predetermined power-saving process data for individual channels of input/output units for at least one power-saving state, that are assigned to the individual input/output units, wherein power-saving profiles for individual channels are defined such that particular bus members can be transferred into power-saving states without knowledge of the particular bus members; accessing the stored power-saving process data of an input/output unit, if the input/output unit has, at least partially, been switched into a power-saving state, wherein then these stored power-saving process data are used instead of process data that is exchangeable between the input/output unit and a connected control unit, via a data transmitting channel; and during switchover into a power-saving state, switching selected channels, with the bus members connected thereto, and, at least partially, the input/output unit into the power-saving state without knowledge of the control unit of controlling the particular bus members, by means of the power-saving process data.

7. The method according to claim 6, wherein storing the predetermined power-saving process data and accessing to these predetermined power-saving process data, if an assigned channel was set into a power-saving state.

8. The method according to claim 6, wherein storing the predetermined power-saving process data takes place in memory units of the input/output units, the control unit, a field bus controller or field bus coupler, interconnected between a control unit and the input/output units, and/or a power-saving control module connected to the data transmitting channel.

9. The method according to claim 6, comprising: group-related storing of predetermined power-saving process data for a group of input/output units or for a group of channels of such input/output units and accessing to the stored power-saving process data of such a group, if the input/output units or channels of the group are set into a power-saving state altogether.

10. The method according to claim 6, comprising: parametrizing of channels of the input/output units with at least one power state comprising at least one predetermined power-saving process datum assigned to the channel to be parametrized, as an output value for the channel, that is taken by the output of the channel instead of a process datum predetermined via a process image by a control unit, and comprising a switching criteria, transmitting of a request for switching of at least one channel of input/output units into a power-saving state comprising a switching criteria to the at least one input/output unit and switching into the power-saving state after checking, by means of the addressed input/output unit, if a power-saving state is parametrized by specification of power-saving process data and if the parametrized switching criteria for the respective channel is fulfilled by the transmitted switching criteria.

11. The method according to claim 6, comprising: parametrizing of channels of the input/output units with at least one power state comprising at least one predetermined power-saving process datum assigned to the channel to be parametrized, as an output value for the channel, that is taken by the output of the channel instead of a process datum predetermined via a process image by a control unit, and comprising a switching criteria, and switching into the power-saving state after checking by means of the control unit or by means of a power-saving control module connected to the data transmitting channel, if a power-saving state is parametrized by specification of power-saving process data and if the parametrized switching criteria for the respective channel is fulfilled by a switching criteria that is currently received together with a switching request for switching of at least one channel of input/output units into a power-saving state, or by a detected switching criteria.

Description

(1) The invention is explained in more detail subsequently by means of an exemplary embodiment and the enclosed figures. It shows:

(2) FIG. 1 a block diagram of a controller comprising a control unit, a field bus controller/-coupler and input/output units connected thereto;

(3) FIG. 2 a flow chart of a method for switching input/output units into a power-saving state.

(4) FIG. 1 shows a block diagram of a controller 1 that comprises a programmable logic controller unit (2) in per se known manner. The programmable logic controller 2 is adapted to execute a control program and to exchange process data P via a field bus 3 with at least one network node 4. The network node 4 comprises a field bus controller/-coupler 5. The field bus controller/-coupler 5 is adapted to convert data between the protocol of the field bus 3 to the communication protocol of an internal proprietary data transmission channel 6 and vice versa. Hereby the field bus controller/-coupler 5 comprises a processing unit 7 as well as a memory unit 8, which is connected thereto. In the memory unit 8 a process data image 9 is stored, in which process data P for the input/output units 10, which are connected to the field bus controller/-coupler 5 via the internal data transmission channel 6, are stored.

(5) Thereby an exchange of process data P takes place, from the process image 9 to the connected input/output units 10 and vice versa, via the data transmission channel 6. In this manner predetermined process data P can be written into the process data image 9 by means of the control unit 2 via the field bus 3. The field bus controller/-coupler 5 transmits these process data P from the process data image 9 to the input/output units 10, e.g. cyclic according to the communication protocol of the data transmission channel 6. These input/output units 10 can itself write process data P into the process data image 9 via the data transmission channel 6. These process data P can then be transferred from the field bus controller/-coupler 5 to the control unit 2 via the field bus 3.

(6) The input/output units 10 comprise one or a plurality of channels 11a, 11b, . . . , 11n respectively, to which the bus members 12 can be connected. Such bus members 12 can be actuators, sensors or other devices.

(7) The bus members 12 are supplied with electric power (line voltage) via a voltage supply module 13 of the modular arranged node 4. Hereby, it is about a 24 volt, no volt or 220 volt voltage supply for example, which allows a significant higher current flow (>5 ampere) than the voltage supply for the electronic of the node 4, which is provided usually together with the data transmission channel 6.

(8) In order to set individual input/output units 10 or individual channels 11a, 11b, . . . , 11n of the input/output units 10 individually or in groups into a power-saving state in an easy and flexible manner, in which the power consumption is reduced, a parametrization of the channels 11a, 11b, . . . , 11n, with a number of power states E.sub.n from 1 to n, is carried out. A power state E.sub.n is described thereby by two attributes. On the one hand a power-saving process datum V is provided, which describes the output value of the assigned channel, which the channel 11a, 11b, . . . , 11n shall adapt, if this one is switched into the power state. Furthermore a switching criteria C is provided that describes a decision criteria in order to switch into a power state. Thus, the specification of a pause time, e.g. according to the PROFI-energy-standard, can be used as a criteria C. In the sercos energy-standard the criteria C is described by an identification number.

(9) During the engineering, output channels 11a, 11b, . . . , 11n or groups of such output channels of connected input/output units 10 are assigned to at least one power state E.sub.n. The assigned power states E.sub.n can then be stored in a table 14. The power state table 14 can be stored for example in the field bus controller/-coupler 5 of the higher-ranked control unit 2 or also in a memory unit 8, 8, 8 available in the individual input/output units 10. In case that the power state table 14 is stored in the individual input/output units 10, preferably only the power states for the channels 11a, 11b, . . . , 11n of the respective input/output unit 10 are present in the table.

(10) During the engineering, output channels 11a, 11b, . . . , 11n or groups of such output channels of connected input/output units 10 are assigned to at least one power state En. The assigned power states En can then be stored in a table 14. The power state table 14 can be stored, for example, in a memory unit 8 of the field bus controller/-coupler 5, or a memory unit 8 of the higher-ranked control unit 2 or also in a memory unit 8 available in the individual input/output units 10. In case that the power state table 14 is stored in the individual input/output units 10, preferably only the power states for the channels 11a, 11b, . . . , 11n of the respective input/output unit 10 are present in the table.

(11) For a more simple addressing it is thinkable to configure groups of channels 11a, 11b, . . . , 11n or groups of input/output units 10. Thereby the control of power states during operation is simplified, as the configuration of the power states of outputs of bus clamp units is managed. The configuration, management and storing of groups is carried out, for example, by the field bus controller/-coupler 5. The power-saving states of groups can be controlled independent of each other during operation. The field bus controller/-coupler 5 can thereby manage a number of groups from 1 to n.

(12) By the implementation of groups logic units can be formed, e.g. for connected plant components connected via different output channels 11a, 11b, . . . , 11n and bus clamp units (input/output units 10). Different plant components can hereby set into power states decoupled from each other. Time or other dependencies can be respected by the control unit 2.

(13) Moreover, a group can also include all channels 11a, 11b, . . . , 11n of the input/output units 10. Hereby all output channels 11a, 11b, . . . , 11n can be managed by one address and thereby set into power-saving states by one command via the field bus 3.

(14) Thereby power-saving states and/or power-saving functions can be applied to individual channels 11a, 11b, . . . , 11n and any groups of such channels.

(15) On the basis of the right bus member 12 it is obvious, that bus members 12 can also be connected to multiple channels 11a, 11b, . . . , 11n of the same or different input/output units 10. These channels 11a, 11b, . . . , 11n are then clustered to a logic (sub-) group LG, wherein power states E.sub.n are settable altogether for such a logic (sub-) group LG.

(16) The control of power functions can be carried out e.g. via a non-real-time channel of the field bus 3 and/or of the data transmission channel 6. Requests for the control of a power state can thereby be applied to individual output channels 11a, 11b, . . . , 11n and/or output channel groups or to groups of output channels 11a, 11b, . . . , 11n managed by the field bus controller/-coupler 5.

(17) The process for switching into a power-saving state for an output channel 11a, 11b, . . . , 11n is simplified as follows:

(18) 1) A request is carried out by the control unit 2 via the field bus 3 to engage the power state. As a parameter such a request always comprises a criteria C. In case there is a power state E.sub.n configured for the addressed output channel 11a, 11b, . . . , 11n that corresponds to this criteria C, the output of this channel 11a, 11b, . . . , 11n is switched to the assigned power substitute value V as associated predetermined power-saving process datum of the configured power state E.sub.n. The synchronous real-time process data are not mapped to this output channel 11a, 11b, . . . , 11n from this time on.

(19) 2) A request is carried out to leave the power state. The addressed output channel 11a, 11b, . . . , 11n leaves then the power state E.sub.n and switches then into the normal process data exchange e.g. via a process image.

(20) The process for switching into a power state for groups is simplified as follows:

(21) 1) A request is carried out to engage a power state E.sub.n. As a parameter such a request always comprises a criteria C. For every output channel 11a, 11b, . . . , 11n and/or every group of such output channels of the addressed group it is checked, whether a power state E.sub.n with corresponding criteria C is configured. If this is the case, the output of this channel 11a, 11b, . . . , 11n is switched to the associated power substitute value V, i.e. the predetermined power-saving process datum of the configured power state E.sub.n. The synchronous real-time process data are not mapped to these output channels 11a, 11b, . . . , 11n from this time on.

(22) 2) A request is carried out to leave again the power state E.sub.n. All configured output channels 11a, 11b, . . . , 11n of the addressed group leave then their power state E.sub.n, insofar as they are in such, and switch back into the normal process data exchange.

(23) The method becomes more obvious with the help of FIG. 2.

(24) In a step 20 a configuration is carried out as predetermined power-saving process data V (power substitute values) assigned to the individual input/output units 10 and/or their channels 11a, 11b, . . . , 11n are stored for a power-saving state E.sub.n.

(25) During operation, in which a control unit 2 runs for example a programmable logic controller program, individual channels 11a, 11b, . . . , 11n or groups thereof as well as individual selected input/output units 10 and/or groups thereof, can be set into a power-saving state, as needed. Hereby in step 21 it is checked repeatedly during process, whether a stored criteria C, which is predetermined for at least one power state E.sub.n, is fulfilled (is C=C fulfilled?). If this is the case, a switching of the output channels 11a, 11b, . . . , 11n, for which the criteria C is fulfilled, into the power-saving state, is carried out in step 22. Hereby an access to the stored power-saving process data V (power substitute values) of the affected input/output units 10 and/or the affected channels 11a, 11b, . . . , 11n is carried out, wherein then these stored power-saving process data V are used instead of process data that are exchangeable between the input/output unit 10 and a control unit 2, 5 that is connected via a data transmission channel 6 thereto.

(26) In the described embodiment the switching into the power-saving state can also be carried out by means of the field bus controller/-coupler 5 itself as a control unit without a higher-ranked control unit 2 or autonomously by the input/output units 10. It is thereby merely required that the field bus controller/-coupler 5 or the input/output units 10 are able to check, by means of appropriate hard- and/or software, the existence of a criteria C by means of process data or control data provided, to switch then into the power-saving state.