FI91682C - System for controlling process racking devices - Google Patents

Description

91682 System for controlling process actuators

The invention relates to a system for controlling process actuators in an automation system, in which 5 actuators, such as motors and valve actuators, are controlled by means of one or more logic circuits (1) belonging to the automation system: In particular, the invention relates to is logically grouped into 10 separate units, the controllers of the actuators contained in which can be addressed by means of an address bus.

In industrial process systems, in which actuators 15, such as motors, e.g. pumps and agitators or actuators for valves or mixers, are automatically controlled by means of a computer or the like, control is traditionally controlled by direct control, i.e. the control logic outputs are connected directly. output to the controlled actuator.

20 The disadvantage of such an arrangement is the large amount of cabling required for the control logic, as well as the very modest utilization rate of the capacity and features of the automation system. In this context, an automation system means, for example, a system based on programmable logic, a process station, a microcomputer or the like, by means of which the process can be controlled automatically.

In the control of known process devices, a serial bus is also used, but it has the disadvantage of the high cost and slowness of the actuator controllers and the complexity of the control protocol of the control logic. The known controllers of the actuators controlled by logic (1), which can be addressed by means of an address bus, also use complex bus solutions, and yet, for example, the status information 35 of the actuators cannot be read without additional equipment or logic.

2 91682 The object of the present invention is to further develop the control of process actuators in such a way that the cabling required for the automation system is reduced and in such a way that its capacity is still substantially increased. To achieve this 5, the system according to the invention is characterized in that - the first part of the logic poles is formed as a common parallel address bus for the groups of actuator controllers; 10 - the second part of the poles of the logic circuit is formed as control and status information lines for each control group of the actuators, by means of which the controller addressed by the address bus can be commanded and its status information can be read.

The advantage of the control of the process actuators implemented with the system according to the invention is the simplicity, speed and small number of conductors of the parallel control compared to the conventional direct control. Because the assignment of a particular device is simple, no complex electronics per device or parallel transfer protocol is required for the parallel bus.

Other preferred embodiments of the method according to the invention are characterized by what is stated in the claims below.

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which Figure 1 shows a process actuator control system implemented in accordance with the invention, and Figure 2 shows a corresponding process actuator control system implemented in a known manner.

Figure 3 shows the actuator controller and actuator electronics connected to an automation system according to the invention.

Figure 1 thus shows a system according to the invention.

II

91682 3 a control part of an automation system operating according to a system, comprising a control logic circuit 1, which in this example case is a programmable logic circuit. It could just as well be a microprocessor-controlled circuit. In addition to the logic circuit 1, the control section includes the required number (in this example case 4) of group control centers 2, ... 24, each of which has, for example, 16. actuator controller (not drawn, see Figure 3). Each controller is normally able to control one process-10 actuator 3, so the capacity of the whole group becomes 16. electric motors or valve actuators (eg solenoid).

Logic circuit 1 and group control centers 2, ... 24 are connected by a parallel address bus 4 according to the invention.

15 Based on the signal on address bus 4, in each group control device the the actuator controller at the address (if one is connected to the group control in question) identifies itself as being assigned. If the address bus itself is e.g. 4-bit, it can address the said 16 to 20 pieces. actuators in each group control center 2v..24.

The signal common to all group control centers is also an activation signal 5, which informs the group controls when the control information is readable on the line 6 transmitting the control signal 25. This is essential because the data transmission between the logic circuit 1 and the group control available as long as the activation signal is high. In this way, e.g. the advantage that the actuator controllers are independent of the speed of the control logic, which allows their use with all control logics and also allows the reception and transmission of analog control and status information messages (e.g. frequency information, office information).

In the system according to the invention, the actuator controllers 21 ... 24 of the group control centers 4 91682 are thus commanded by group-specific control information signals 6, and in part the address in question is also indicated. signal. This occurs when the activation signal is active, i.e. "up". The signal 6 can be used, for example, to instruct the selected actuator controller to start / stop the actuator it controls. It should be noted that according to this embodiment of the invention, only the presence of the group-specific signal 6 confirms in which group the actuator controller actually located is located, and thus finally identifies it (cf. Fig. 3).

The status information signals are automatically provided to the logic circuit 1 via the signal path 7. Ko. the status and error information is read from the assigned actuator controllers regardless of the group and the status of the activation signal 5 whenever the logic circuit 1 sets the address on the address bus. This can be done, for example, routinely at certain intervals.

On the other hand, there may be applications where it is advantageous to control several actuators at exactly the same time. This can be easily achieved by giving the the same address for the devices, and by activating all the necessary groups at the same time. By changing the size and number of groups, the ratio of bus speed to lines can be optimized in each application.

Assignment methods other than those mentioned above can be considered, such as an extended address bus capable of group assignment, but the method described above requires the encoding and decoding of a minimum number of addresses. In addition, some form of direct assignment is usually necessary because this method is the least sensitive to the signaling protocol used by the actuator and its controller, which may be based on binary information, analog signal, or serial communication. In this case, the control implemented according to the invention also does not impose any restrictions on the quality of the actuators used.

Figure 2 shows a prior art

II

91682 5 ti implemented in a process actuator control system in which e.g. the same programmable logic circuit 1 as in the solution according to Fig. 1 is used, but in which each actuator controller 8 is connected directly to two ports of the logic circuit 5 for transmitting instructions and status information. Thus, if there are 16 ports in logic circuit 1, 8 actuator controllers can be assigned in this way. The corresponding number in the arrangement according to Fig. 1 is 80 on the 4-bit address bus in practice, divided into four groups of 10 controllers.

Figure 3 shows a more detailed example of the actuator controller and actuator electronics connected to the automation system according to the invention. It shows the buses and signals according to Fig. 1 with the corresponding reference numerals, except that there are two lines indicating status information, line 7a (disturbance) and line 7b (start / stop). The actual actuator controller is denoted by reference numeral 9, the output of which has connections for electric motor contactors, safety switches, etc. The electronics 20 belonging to the actuator itself are denoted by reference numeral 10. The connections will not be described in detail here, as the operation of the devices is .

From the point of view of the invention, it is essential to detect the coupling mat-25 rice 11, in which the for the actuator, its 4-bit address. It should also be noted that the actuator controller group centers according to Figure 1 do not need to contain anything other than the controller devices themselves; intra-group address identification and group-specific operation / read instruction unambiguously defines an actuator to be controlled without any special group control electronics, and without being tied to a particular signaling protocol, because the automation system can be controlled by a different system.

6,91682

It will be apparent to those skilled in the art that the various embodiments of the invention are not limited to the example set forth above, but may vary within the scope of the following claims.

Claims (3)

7 91. B'z A system for controlling processoidin devices in an automation system, wherein actuators, such as 5 motors and valve actuators, are controlled by one or more logic circuits (1) included in the automation system, and wherein the actuators (3) controlled by the logic (1) have grouped controllers (3) as separate units (2, -24), the controllers (10) of the actuators contained therein can be addressed by means of an address bus, characterized in that - the first part of the poles of the logic (1) is formed for the groups of actuator controllers (2, -2 ^) as a common parallel address bus; 15. The second part of the terminals of the logic circuit (1) is formed as control and status information lines (6, 7) for each actuator control group (21-24), by means of which the controller indicated by the address field can be commanded and its status information can be read. A system according to claim 1, characterized in that a common activation signal line (5) is connected between the logic circuit (1) and the groups of actuator controllers (2, -2,.), On the basis of the activation signal of which each assigned actuator controller (10) reads the status of its control signal (6). System according to Claim 1 or 2, characterized in that the individual actuator controller (10) of the automation system is identified on the basis of the address contained in the address field (4) and the control group-specific control signals (6). 8 9. obz