GB2202065A

GB2202065A - Cigarette machine control

Info

Publication number: GB2202065A
Application number: GB8806006A
Authority: GB
Inventors: Michael John Cahill; David Christopher Mille Carter; Keith Kidd; John Kenneth Price; Martin Christopher Rule
Original assignee: Molins Ltd
Current assignee: Mpac Group PLC
Priority date: 1987-03-13
Filing date: 1988-03-14
Publication date: 1988-09-14
Also published as: GB8706068D0; GB8806006D0; WO1988007227A1

Abstract

A cigarette making machine or other machine of the cigarette industry includes a control apparatus for monitoring and controlling the machine and including a number of control devices each of which detects a condition in part of the machine or controls the operation of part of the machine, each device being connected to a node module (26; 28; 30) which is mounted on a common ribbon cable (24; 12) connected to a controller (22), each node module including connectors (11) which penetrate the insulation of the ribbon cable to make contact with respective wires in the ribbon cable, and an integrated circuit arranged to interface between the controller and the respective control device. <IMAGE>

Description

Cigarette Machine Control This invention is concerned with apparatus for monitoring and controlling the operation of a machine of the cigarette industry such as a cigarette making machine or packing machine, but it has wider applicability. This -invention is in some respects a further development of the invention described in our British patent No.

2055235, to which reference is directed in its entirety.

According to this invention, in a control apparatus for monitoring and controlling a machine having a number of control devices each of which detects a condition in part of the machine or controls the operation of part of the machine, each device is connected to a node module which is mounted on a common ribbon cable connected to a controller, each node module including connectors which penetrate the insulation of the ribbon cable to make contact with respective wires in the ribbon cable, and an integrated circuit arranged to interface between the controller and the respective control device.

Each control device may for example, be either a 2-state device providing a YES or NO signal, e.g. a condition-monitoring transducer, or an analogue device (or equivalent digital device) providing a multiply variable signal. In terms of the present invention, a 2state device needs a relatively simple interface with the controller, the node needed for that purpose being here termed a "dumb" node. The alternative is an 11intel ligent'1 device which requires more complex interfacing with the controller; a "smart" node is needed for that purpose. Each smart node is preferably made up from a standard dumb node with an additional circuit which may be housed in a separate encapsulated body.The integrated circuit of each dumb node is preferably potted in a block of insulating material provided with protruding connectors for penetrating the ribbon cable or with sockets to receive connector pins mounted on a separate part having connectors for engaging the ribbon cable. In use, any appropriate number of node modules can be attached to the ribbon cable, each being preferably detachable to enable a replacement to be made of a faulty module.

Each node may serve either an input or an output device. An example of a 2-state input device is a proximity probe which merely indicates whether or not a part (e.g. part of the machine, or material being processed) is in its vicinity; such a device requires only a dumb node. An example of an output device also requiring only a dumb node is a pneumatic actuator arranged, for example, to move or operate part of the machine in response to a signal from the controller. A smart node might be needed, for example, for a tachometer (an input device) or by a stepper motor as an example of an output device.

An example of apparatus according to this invention is shown in the accompanying drawings. In these drawings: Figure 1 is an exploded view of one node module; and Figure 2 illustrates diagrammatically a control loop including a controller and a number of nodes.

Figure 1 shows a node module comprising a part 10 formed with pairs of connectors 11 which penetrate through the insulation covering the individual wires of a ribbon cable 12 so that each pair grips and forms an electrical connection with one wire or strand in the cable.

The part 10 is mounted in a block 18 in which is embedded an appropriate integrated circuit comprising, for example, a gate array.

The part 10 may be separable from the block 18; for example, each pair of connectors may extend from a pin which projects from the opposite face of the part 10 and engages in a corresponding socket in the block 18 to form an electrical connection with a printed circuit board embedded in the block.

A plate 14 forms a backing for the ribbon cable, as the connectors 11 are pushed through the cable insulation, and then is clamped or otherwise secured onto the block 18. The edges of the plate 14 seal around the ribbon cable.

A lead 20 connects the block to a corresponding transducer or other control device. In the case of a smart node, the lead may be in the form of a ribbon cable to accommodate the required number of wires.

In practice, the ribbon cable may be housed in a duct, and it is an important feature of this invention that each node module is relatively compact so that it can lie within the duct for protection.

The lead 20 passes to the corresponding input or output device. In the case of an analogue device, the lead 20 may pass to it via a separate block containing additional circuitry; alternatively, the block 18 in the case of an analogue device may itself contain the necessary additional circuitry.

Figure 2 shows diagrammatically a complete apparatus including a controller 22 comprising a microcomputor, a ribbon cable 24 forming a closed loop, and three nodes 26, 28 and 30 having leads 26A, 28A and 30A leading to corresponding control devices. In this example, the node 28 comprises a common dumb node which is connected via the lead 28A to an analogue device via further circuitry housed in a block 32.

In use, the nodes on the loop are enabled sequentially by sequential response to a token signal passed along one wire of the ribbon cable. This signal carries a sequence of address codes and each node is enabled when the code corresponds to its address. The address of each node is set by manually setting the switches in a switch block 13 which is mounted in the block 18 and is accessible before the block is secured to the ribbon cable.

While a node is enabled, it can send or receive data. Data links may typically be in a range extending from 1 bit for a 2-state device to 16 bits or more for a more complex device such as an analogue device. In a typical machine of the cigarette industry, approximately 80% of the control devices may be 2-state devices.

Additional electronics is needed for the remaining devices each of which may be a multi-channel digital or analogue device or a bidirectional device.

Each of the switch blocks 13 may establish a unique address for the corresponding node. Alternatively, anumber of dumb nodes (for example for material presence detectors) may be given the same address so that they are enabled simultaneously, a fault or ON signal from any one of them being a sign that the machine is, for example, to be stopped automatically. This could enable the controller to complete each cycle more rapidly. Alternatively, each node may have a unique address, and simultaneous enabling of a number of dumb nodes may be achieved through the software in the controller.

The ribbon cable serves to conduct signals and also low power sufficient for the interface electronics in the nodes. High power may be distributed separately to those devices that need it.

The ribbon cable preferably forms a loop as shown in Figure 2.

This enables each signal to or from the controller to be transmitted in both directions for added security, and allows more power to be passed along the power-conducting wires. The controller may moreover be arranged to detect a break in the cable (or in at least some of the wires) by detecting that signals are being received by it via only one end of the ribbon cable instead of from both ends.

With this system, in one specific example, on a 10 metre loop with 100 nodes, it is possible to achieve a resolution of 1 millisecond; in other words, the time for completing a cycle taking in all the nodes in turn is 1 millisecond. However, if different speeds of response are needed by different devices, more than one loop may be included in the machine for accommodating the different speed requirements and possibly for splitting up the control devices according to types of function.

Self-test facilities may be built into the nodes and controller to facilitate fault recognition and diagnosis. For example, such facilities may allow each node to signal to the controller that it has a fault or that data integrity is poor.

It will be appreciated that any additional control devices required for a machine fitted with apparatus according to this invention may readily be accommodated simply by clamping onto the ribbon cable the required node module or modules.

Compared with prior systems, this invention allows for a reduction in wiring and design costs.

Claims

1. A cigarette making machine or other machine of the cigarette industry including a control apparatus for monitoring and controlling the machine and including a number of control devices each of which detects a condition in part of the machine or controls the operation of part of the machine, each device being connected to a node module (26;28;30) which is mounted on a common ribbon cable (24;12) connected to a controller (22), each node module including connectors (11) which penetrate the insulation of the ribbon cable to make contact with respective wires in the ribbon cable, and an integrated circuit arranged to interface between the controller and the respective control device.

2. A control apparatus for monitoring and controlling a machine, especially of the cigarette industry, including a number of control devices each of which each detects a condition in part of the machine or controls the operation of part of the machine, each device being connected to a node module (26;28;30) which is mounted on a common ribbon cable (24;12) connected to a controller (22), each node module including connectors (11) which penetrate the insulation of the ribbon cable to make contact with respective wires in the ribbon cable, and an integrated circuit arranged to interface between the controller and respective control device.

3. A machine or control apparatus according to claim 1, in which each node module comprises a standard component plus, in the case of node modules for certain of the control devices, an additional circuit for processing multiply variable signals.

4. A machine or control apparatus according to claim 3 in which at least one of the additional circuits is contained in a block separate from the corresponding standard node component.

5. A machine or control apparatus according to claim 3 or claim 4 in which at least part of the circuit included in each node module comprises a gate array which is potted in a block forming part of the node.

6. A machine or control apparatus according to any one of claims 1 to 5 in which each node module comprises two parts (10,18;14) which are secured together on opposite sides of the ribbon cable (12).

7. A machine or control apparatus according to claim 6 in which the two parts have edge portions arranged substantially to form a seal around the ribbon cable.

8. A machine or control apparatus or according to any one of claims 1 to 7 in which each node module includes means defining an address whereby the controller can enable the control devices in a predetermined sequence.

9. A machine or control apparatus according to claim 7 in which the address for each node module is determined by a manually settable switch or set of switches (13) accessible before the node module is mounted on the ribbon cable (12).

10. A machine or control apparatus according to any one of claims 1 to 9 in which the ribbon cable forms a closed loop, both ends being connected to the controller.

11. A machine or control apparatus according to claim 10 in which the controller includes means for detecting the occurence of a break in at least certain of the wires of the ribbon cable indicated by receipt of a signal from only one end of the ribbon cable.

12. A machine according to claim 1 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.

13. A control apparatus according to claim 2 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.