The present invention relates to a control system for a liquid dosing apparatus. In particular, the invention relates to a control system for dosing chemicals, such as cleaning chemicals, for industrial laundry machines.

Control systems for industrial laundry machines are known, and are configured to supply a dosed amount of a chemical to the laundry machine on demand. In general, the laundry machine supplies a trigger signal to the control system to initiate a single dose of a single chemical, or in some instances the trigger signal can initiate a sequence of dosing of multiple chemicals.

One particular liquid dosing apparatus and control system is supplied by the applicant under the name EvoClean (RTM). The apparatus comprises multiple venturi-based water- powered chemical dosing units. Each dosing unit has a water inlet, a chemical inlet, an outlet, and an electrically controllable valve. The water inlet is coupled to a constriction portion of the venturi, leading to a throat, the outlet being coupled to a diffusion portion of the venturi, leading away from the throat. The chemical inlet is coupled to the venturi at the throat, such that upon water flow through the venturi a vacuum is caused at the throat which draws chemical into the water flow to be mixed with the water. The chemical and water mix flows out of the outlet. The valve, such as a solenoid valve, controls the flow of water through the venturi.

In the known EvoClean (RTM) system, each of the multiple dosing units are coupled to a manifold having an outlet which can be coupled to the laundry machine. In addition, a flush unit is provided to provide only water to the manifold. The flush unit is of similar construction to the chemical dosing units, except that the inlet coupled to the throat of the venturi is coupled to atmosphere, via a one-way check valve. Upon activation of the flush unit, air is drawn into the flush unit by the vacuum caused by the water flow through the venturi. In addition, the check valve enables air to be drawn into the manifold, allowing it to drain, upon a negative head of pressure being generated in the manifold; for example, such a negative head of pressure where the discharge is below the unit.

The manifold of the known EvoClean (RTM) system is coupled by tubing to the laundry machine, and in order to suitably locate the system it may be many metres away from the laundry machine.

It is thus an object of the present invention to provide an improved control system for a liquid dosing apparatus. According to a first aspect of the present invention, there is provided a control system for a fluid dosing apparatus. The apparatus comprises: at least two fluid dosing units; a flush fluid unit; and a manifold configured to couple the at least two fluid dosing units and the flush fluid unit to a fluid outlet. The control system comprises: dosing module, configured to activate the at least two fluid dosing units; a flush module, configured to activate the flush fluid unit; a delay module, configured to receive a delay time for delaying activation of a second one of the at least two fluid dosing units after activation of a first one of the at least two fluid dosing units, and to determine whether the delay time is greater than a predetermined threshold. Upon the delay time being greater than the threshold, the delay module is configured to control the flush module to activate the flush fluid unit after the dosing module activates the first one of the at least two fluid dosing units, and before the dosing module activates the second one of the at least two fluid dosing units.

By providing such a control system, advantageously, the dosed fluids do not remain within the supply tubing which couples the dosing apparatus to the equipment being supplied with the fluids. The equipment may be a laundry machine. This is because, ordinarily, the dosing apparatus controls the volume of dosed fluid by activating the dosing units for a specified time period. If a significant delay is provided between dosing a first fluid and dosing a second fluid, the first fluid may remain within the supply tubing for that delay period. This can adversely affect the performance of the equipment, for example due to the chemical degrading the supply tubing, or because all of the chemical is not delivered to the laundry machine at the correct time. In addition, where the fluids being dosed are chemically incompatible, it may be important to ensure they do not mix within the supply tubing. By providing a flush event between the dosing events, the likelihood of the dosing fluids mixing within the supply tubing may be reduced. Furthermore, some fluids may be mixtures such as an emulsion, colloid, or suspension which may separate into the constituent parts, e.g. by sedimentation, if they remain for too long within the supply tubing.

As will be appreciated, the fluids being dosed are preferably liquid and may be Newtonian or non-Newtonian fluids. In one particularly preferred embodiment, the dosed fluids are liquid chemicals for industrial laundry machines.

The predetermined threshold may be between about 10 seconds and about 60 seconds, preferably between about 20 seconds and about 50 seconds, more preferably between about 35 seconds and about 45 seconds, and in one embodiment the predetermined threshold is about 39 seconds. It is important that the threshold time is neither too long, nor too short. It has been recognised that where the threshold time is too short, the number of times the flush fluid unit is activated rises to be significantly higher than each of the fluid dosing units. Such a scenario may lead to failures of the flush fluid unit, reducing the period between maintenance, and reducing the overall lifespan of the system. If the threshold time is too long, the advantages provided by the invention may not be fully realised.

The system may further comprise a storage module, configured to store, for each of the at least two fluid dosing units, an activation time (that is to say the duration of activation), at least one delay time, and a flush time, wherein the storage module is configured to provide the delay module with the delay time.

Upon the delay time being less than the flush time, the delay module may be configured to control the flush module to activate the flush fluid unit substantially constantly during the delay between the end of the activation of the first one of the at least two fluid dosing units, and the start of the activation of the second one of the at least two fluid dosing units.

The flush time may be between about 2 seconds and about 999 seconds, preferably between about 2 seconds and about 300 seconds, more preferably between about 2 seconds and about 100 seconds.

The delay module may be further configured to select one of a plurality of predetermined thresholds in dependence on the type of fluid being dosed by the first one of the at least two fluid dosing units. The delay module may be further configured to select one of a plurality of predetermined thresholds in dependence on the type of fluid being dosed by the second one of the at least two fluid dosing units. The delay module may be further configured to select one of a plurality of predetermined threshold in dependence on both the type of fluid being dosed by the first one of the at least two fluid dosing units and the type of fluid being dosed by the second one of the at least two fluid dosing units. The delay module, or where provided storage module, may comprise a look-up table comprising a plurality of predetermined thresholds, each predetermined threshold associated with a type of fluid to be dosed. Where the predetermined threshold is selected in dependence on both the types of fluid being dosed, the look-up table may comprise a plurality of predetermined thresholds, each predetermined threshold associated with the combination of types of fluid to be dosed.

In this way, the threshold time may be optimised for each of the fluids to be dosed. For example, fluids to be dosed which may result in operational issues if they remain within the supply tubing for too long may be associated with a shorter threshold time than those fluids to be dosed which would not result in such operational issues.

Furthermore, fluids to be dosed which do not require separation from other fluids may be associated with a longer threshold time before a flush operation is provided between dosing the two fluids. Alternatively, where the fluids to be dosed must be separated from each other, that combination of fluids may be associated with a shorter threshold time. Advantageously, this may enable the use of the flush fluid unit to be minimised without reducing the advantages associated with providing a flush operation between dosing two different fluids.

The flush module may be further configured to activate the flush fluid unit after the end of the activation of the second one of the at least two fluid dosing units. Advantageously, this enables the second one of the dosing fluids to be flushed through the supply tubing.

The fluid dosing apparatus may comprise at least three fluid dosing units. In this embodiment, the delay module of the controller is further configured to receive a second delay time for delaying activation of a third one of the at least three fluid dosing units after activation of the second one of the at least three fluid dosing units, and determine whether the second delay time is greater than a predetermined threshold. Upon the second delay time being greater than the threshold, the delay module is configured to control the flush module to activate the flush fluid unit after the dosing module activates the second one of the at least two fluid dosing units, and before the dosing module activates the third one of the at least two fluid dosing units.

When the fluid dosing apparatus comprises three or more fluid dosing units, it will be appreciated that the ordered combination of pairs of dosing units which may be activated one after the other increases. As used herein the term "pair" of dosing units refers to the series of fluid dosing units activated one after the other. Where the apparatus comprises two dosing units, there are two combinations: first then second; and second then first. Where the apparatus comprises three dosing units, there are six combinations: first then second; first then third, second then first; second then third; third then first; and third then second. Each combination may be associated with the same, or different predetermined threshold.

As will be appreciated, the fluid dosing apparatus may comprise four, five, six, seven, eight or more fluid dosing units, the delay module of the controller being correspondingly configured to receive delay times and determine whether that delay time exceeds a predetermined threshold for each pair of fluid dosing units being activated by the dosing module. Furthermore, the number of ordered combinations of pairs of dosing units increases significantly with each additional dosing unit.

The control system preferably further comprises a trigger module, configured to receive a trigger signal for triggering the dosing module to activate the first one of the fluid dosing units. The trigger module is preferably configured to activate a pre-programmed series of trigger events for triggering the dosing module to activate a plurality of the at least two dosing units. The trigger signal may be provided by the equipment being supplied with the dosed fluid. Each of the fluid dosing units preferably comprises a venturi eductor, comprising an inlet, an outlet and a dosing fluid inlet, the inlet being in fluid communication with a water supply, the outlet in fluid communication with the manifold, and the dosing fluid inlet in fluid communication with a source of dosing fluid and a throat of the venturi.

Each flush fluid unit preferably further comprises a solenoid configured to open a valve and enable flush fluid flow through the flush fluid unit.

According to a further aspect of the present invention, there is provided a method for controlling a fluid dosing apparatus. The apparatus comprises: at least two fluid dosing units; a flush fluid unit; and a manifold configured to couple the at least two fluid dosing units and the flush fluid unit to a fluid outlet. The method comprises: activating a first one of the at least two fluid dosing units; receiving a delay time for delaying activation of a second one of the at least two fluid dosing units after activation of the first one of the at least two fluid dosing units; and determining whether the delay time is greater than a predetermined threshold. Upon the delay time being greater than the threshold, the method comprises activating the flush fluid unit after activation of the first one of the at least two fluid dosing units, and before the activation of the second one of the at least two fluid dosing units.

By providing such a method, advantageously, the dosed fluids do not remain within the supply tubing which couples the dosing apparatus to the equipment being supplied with the fluids. This is because, ordinarily, the dosing apparatus controls the volume of dosed fluid by activating the dosing units for a specified time period. If a significant delay is provided between dosing a first fluid and dosing a second fluid, the first fluid may remain within the supply tubing for that delay period. This can adversely affect the performance of the equipment, for example due to the chemical degrading the supply tubing, or because all of the chemical is not delivered to the laundry machine at the correct time. In addition, where the fluids being dosed are chemically incompatible, it may be important to ensure they do not mix within the supply tubing. By providing a flush event between the dosing events, the likelihood of the dosing fluids mixing within the supply tubing may be reduced. Furthermore, some fluids may be mixtures such as an emulsion, colloid, or suspension which may separate into the constituent parts, e.g. by sedimentation, if they remain for too long within the supply tubing.

As stated above, the fluids being dosed are preferably liquid, and may be Newtonian or non-Newtonian fluids. In one particularly preferred embodiment, the dosed fluids are liquid chemicals for industrial laundry machines.

The predetermined threshold is preferably between about 10 seconds and about 60 seconds, preferably between about 20 seconds and about 50 seconds, more preferably between about 35 seconds and about 45 seconds, and in one embodiment the predetermined threshold is about 39 seconds. It is important that the threshold time is neither too long, nor too short. It has been recognised that where the threshold time is too short, the number of times the flush fluid unit is activated rises to be significantly higher than each of the fluid dosing units. Such a scenario may lead to failures of the flush fluid unit, reducing the period between maintenance, and reducing the overall lifespan of the system. If the threshold time is too long, the advantages provided by the invention may not be fully realised.

Preferably, each of the at least two fluid dosing units are activated for an activation time, and the flush fluid unit is activated for a flush time. The method may comprise receiving said activation times and said flush time as inputs from a user, and storing said times.

Upon the delay time being less than the flush time, the flush fluid unit may be activated substantially constantly during the delay between the end of the activation of the first one of the at least two fluid dosing units, and the start of the activation of the second one of the at least two fluid dosing units.

The flush time may be between about 2 seconds and about 999 seconds, preferably between about 2 seconds and about 300 seconds, more preferably between about 2 seconds and about 100 seconds.

The step of determining whether the delay time is greater than a predetermined threshold may further comprise selecting one of a plurality of predetermined thresholds in dependence on the type of fluid being dosed by the first one of the at least two fluid dosing units. The step of determining whether the delay time is greater than a predetermined threshold may yet further comprise selecting one of a plurality of predetermined thresholds in dependence on the type of fluid being dosed by the second one of the at least two fluid dosing units. The step of determining whether the delay time is greater than a predetermined threshold may yet further comprise selecting one of a plurality of predetermined thresholds in dependence on both the type of fluid being dosed by the first one of the at least two fluid dosing units and the type of fluid being dosed by the second one of the at least two fluid dosing units.

The step of determining whether the delay time is greater than a predetermined threshold may further comprise addressing a look-up table comprising a plurality of predetermined thresholds, each predetermined threshold associated with a type of fluid to be dosed. Where the predetermined threshold is selected in dependence on both the types of fluid being dosed, the look-up table may comprise a plurality of predetermined thresholds, each predetermined threshold associated with the combination of types of fluid to be dosed. In this way, the threshold time may be optimised for each of the fluids to be dosed. For example, fluids to be dosed which may result in operational issues if they remain within the supply tubing for too long may be associated with a shorter threshold time than those fluids to be dosed which would not result in such operational issues.

Furthermore, fluids to be dosed which do not require separation from other fluids may be associated with a longer threshold time before a flush operation is provided between dosing the two fluids. Alternatively, where the fluids to be dosed must be separated from each other, that combination of fluids may be associated with a shorter threshold time.

Advantageously, this may enable the use of the flush fluid unit to be minimised without reducing the advantages associated with providing a flush operation between dosing two different fluids.

The method may further comprise activating the flush fluid unit after the end of the activation of the second one of the at least two fluid dosing units. Advantageously, this enables the second one of the dosing fluids to be flushed through the supply tubing.

The fluid dosing apparatus may comprise at least three fluid dosing units, the method further comprising receiving a second delay time for delaying activation of a third one of the at least three fluid dosing units after activation of the second one of the at least three fluid dosing units; and determining whether the second delay time is greater than a predetermined threshold. Upon the second delay time being greater than the threshold, the flush fluid unit is activated after the second one of the at least two fluid dosing units is activated, and before the third one of the at least two fluid dosing units is activated.

When the fluid dosing apparatus comprises three or more fluid dosing units, it will be appreciated that the ordered combination of pairs of dosing units which may be activated one after the other increases. Where the apparatus comprises two dosing units, there are two combinations: first then second; and second then first. Where the apparatus comprises three dosing units, there are six combinations: first then second; first then third, second then first; second then third; third then first; and third then second. Each combination may be associated with the same, or different predetermined threshold.

As will be appreciated, the fluid dosing apparatus may comprise four, five, six, seven, eight or more fluid dosing units, the method correspondingly receiving delay times and determining whether that delay time exceeds a predetermined threshold for each pair of fluid dosing units to be activated. Furthermore, the number of ordered combinations of pairs of dosing units increases significantly with each additional dosing unit.

The method preferably further comprises receiving a trigger signal for triggering activation of the first one of the fluid dosing units that is selected. The trigger signal may activate a pre-programmed series of events for triggering activation of a plurality of the at least two dosing units. The trigger signal may be provided by the equipment being supplied with the dosed fluid.

According to a further aspect of the present disclosure, there is provided a control system for a fluid dosing apparatus. The apparatus comprises: at least two fluid dosing units; a flush fluid unit; and a manifold configured to couple the at least two fluid dosing units and the flush fluid unit to a fluid outlet, wherein each fluid dosing unit and the flush fluid unit are electrically actuatable upon receipt of a trigger signal. The control system comprises: an input module configured to receive an input; and a power module configured to, upon activation by a user input, electrically isolate each of the fluid dosing units and the flush fluid unit from a trigger signal. The input module is configured to: receive an input from a user indicating that the power module should be activated to effect the electrical isolation; and send a corresponding signal to the power module.

Advantageously, providing such a power module and input module enables the control system to be isolated from any trigger signals, initiated by equipment being supplied by the fluid dosing apparatus. For example, upon the equipment being maintained, the maintenance operative provides the input to the control system to activate the power module and electrically isolate the dosing units and flush unit from any trigger signals that may be sent by the equipment during maintenance. In this way, the safety of the system is improved.

Preferably, the input module is further configured to: receive an input from the user indicating that the power module should be deactivated; and send a corresponding signal to the power module. The input module may further comprise a code sub-module configured to receive a deactivation code from the user. In this way, the control system may not be reactivated until a reactivation code is received.

The control system may further comprise an indicator, configured to indicate to a user upon the power module being activated. The indicator may be visual, and/or audible. The visual indicator may flash, or be constant.

The indicator may be configured to issue an audible indication upon receipt of a trigger signal. In this way, advantageously, the user is made aware that a trigger signal was received from the equipment. In this scenario, either the received signal was a stray trigger signal caused by the maintenance, or the user did not deactivate the power module after completing the maintenance operation.

According to a yet further aspect of the present disclosure, there is provided a control system for a fluid dosing apparatus. The apparatus comprises: at least two fluid dosing units; a flush fluid unit; and a manifold configured to couple the at least two fluid dosing units and the flush fluid unit to a fluid outlet. The control system comprises: a storage module for storing: a plurality of settings, the settings being at least one of: a duration of activation of one of the at least two dosing units; a duration of activation of the flush fluid unit; an order of activation of the at least two dosing units; and at least one delay time between activation of the at least two dosing units; and a usage report comprising an activation count for each of the at least two dosing units; an access module, configured to receive a first access code to enable access to all of the plurality of settings and the usage report, and a second access code to enable access only to the usage report.

Advantageously, providing such a system enables a low-level user to access a usage report without providing full access to the settings of the control system. In this way, the low- level user is prevented from changing the settings of the control system.

Preferably, the control system comprises a port configured to receive a removable storage module, the control system being configured to download the usage report to the removable storage module upon the access module receiving the second access code.

In one embodiment, upon the port receiving the removable storage module, the access module substantially immediately prompts the user for the second access code.

The control system may further comprise an input configured to receive at least one of: start date for usage report; end date for usage report; and usage report file name. The received input is used to compile the usage report, before downloading the report to the removable storage module.

The storage module of the control system may be further configured to store a plurality of reports, including at least one usage report and at least one of: a set-up report; and an event report. The access module is further configured to enable access to all of the plurality of settings and all of the plurality of reports upon receipt of the first access code.

Where functional modules are referred to in apparatus embodiments for carrying out various steps of the described method(s) it will be understood that these modules may be implemented in hardware, in software, or a combination of the two. When implemented in hardware, the modules may be implemented as one or more hardware modules, such as one or more application specific integrated circuits. When implemented in software, the modules may be implemented as one or more computer programs that are executed on one or more processors.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination. It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

- Figure 1 shows a control system according to one embodiment of the present invention, integrated into a fluid dosing apparatus;

- Figure 2 shows the fluid dosing apparatus shown in Figure 1 ;

- Figure 3 shows a schematic diagram of the control system according to one embodiment of the present invention;

- Figure 4 shows an alternative control system according to another embodiment of the present disclosure;

- Figure 5 shows a user interface diagram for the control system shown in Figure 4;

- Figure 6 shows a further alternative control system according to another embodiment of the present disclosure;

- Figure 7 shows a user interface diagram for the control system shown in Figure 6;

- Figure 8 shows an exemplary usage report in accordance with the control system shown in Figure 6; and

- Figure 9 shows a further user interface diagram for the control system shown in Figure 6.

The present disclosure relates to control systems for fluid, in particular liquid, dosing apparatus. In the examples discussed with reference to the accompanying figures the control system and dosing apparatus is for the control and supply of liquid cleaning chemicals and the like for industrial laundry machines. The dosing apparatus is configured to supply a dosed amount of a chemical to the laundry machine on demand. In general, the laundry machine supplies a trigger signal to the control system to initiate a single dose of a single chemical, or initiate a sequence of dosing of multiple chemicals. The sequence is stored in the control system, and is inputted by a user on initial set-up of the system.

One particular liquid dosing apparatus and control system is supplied by the applicant under the name EvoClean (RTM). The apparatus 100, shown in Figure 1 , comprises dosing apparatus 102 which has multiple dosing units 104, a manifold, and a controller 106. Each is described in further detail below.

The dosing apparatus 102 is shown in further detail in Figure 2. The apparatus 102 comprises multiple venturi-based water-powered chemical dosing units 104, and a single flush fluid unit 200. Each dosing unit has a water inlet 202, a chemical inlet 204, an outlet 206, and an electrically controllable valve 208. The water inlet 202 is coupled to a constriction portion of the venturi, leading to a throat, the outlet 206 being coupled to a diffusion portion of the venturi, leading away from the throat. The chemical inlet 204 is coupled to the venturi at the throat, such that upon water flow through the venturi a depression is caused at the throat which draws chemical into the water flow to be mixed with the water. The chemical and water mix flows out of the outlet 206. The valve 208, such as a solenoid valve, controls the flow of water through the venturi. In use, upon activation of the solenoid valve water begins to flow through the venturi and after approximately 2 seconds a vacuum sufficient to begin drawing liquid chemical is formed. In the present example, the dosing apparatus comprises four dosing units, but may comprise three, six, eight, or more. As will be appreciated, each of the dosing units 104 is coupled to a different liquid cleaning chemical.

Each of the multiple dosing units 104 are coupled to an inlet manifold 210, having a water inlet 212, and to an outlet manifold 214 having an outlet 216 which can be coupled to the laundry machine.

The flush fluid unit 200 is provided upstream of the multiple dosing units 104 to provide only water to the outlet manifold 214. The flush unit is of similar construction to the chemical dosing units, except that the inlet coupled to the throat of the venturi is coupled atmosphere via a check valve.

The outlet 216 is coupled by tubing (not shown) to a laundry machine, and in order to suitably locate the system, which may be many metres away from the laundry machine.

Although the examples provided herein show the controller integrated with the dosing apparatus, it will be appreciated that the controller could be provided as a separate, standalone unit, electrically coupled to the dosing unit by wires. Such a stand-alone, remote, controller, may have the full functionality of the integrated controller, or alternatively the main functions of the controller may be within an integrated portion of the controller, the remainder, such as the ability for a user to select a pre-programmed cycle, can be provided in a remote device.

In the present example, the controller and dosing apparatus draws a maximum of 160 mA at 230 v. Existing control and dosing systems may draw up to 5 A at 230 v, and therefore the current invention advantageously requires less power than known systems. The present invention achieves this reduced power operation by implementing low-power techniques such as only polling an external storage drive once, and upon a user pressing a button, and only monitoring for trigger signals upon activation, rather than constantly. The controller enables preset sequences, and doses, of liquid chemicals to be stored in memory as programmable formulas. In one example, the controller can store up to 21 such formulas. Upon receipt of a predetermined trigger signal from the laundry machine, the controller activates the dosing units in the preset sequence to provide the required chemicals at the desired time. Each formula will conclude with a flush operation to flush the chemicals from the supply tubing, and into the laundry machine. The duration of the flush is also programmed into the formula. In addition, delays may be programmed into the formula, for example between activating a first one of the dosing units and a second one of the dosing units.

The trigger signal is received by an optically isolated high impedance input circuit. The trigger signal voltages may range from 24 VAC to 240 VAC at 50 Hz to 60 Hz, or could be 12 VDC to 24 VDC in dependence on the laundry machine. Each trigger signal input connects to a signal input wire and the common. The controller may comprise a plurality of trigger signal inputs.

For example, a signal on trigger 1 will inject the 'prewash' amount for any chemical selected to run. This allows for different volumes of chemical to be injected at different points in the cycle. Once all the chemicals have been injected the flush solenoid will open for the time set so that no chemical is left in the delivery hose.

The controller may comprise multiple modes of operation. For example, "Normal Mode" allows the user to easily select a formula from a list of formulas by navigating to it using the inputs on the controller. Once the formula is shown the laundry machine can then be started and the particular formula is run. Each formula has the option of being named (up to 10 characters). An example of another mode of operation is "Relay Mode" in which the trigger signals are directly linked to the operation of a particular solenoid (chemical). Once a signal is received the solenoid will operate for the length of time that the signal is present. When a signal is received the corresponding solenoid will operate, if during this time another signal is received then once the first solenoid closes the next one will run. If two signals are received at the same time, the lowest numbered solenoid will operate first followed by the next lowest, for the length of time the signal is/was present. Furthermore, if a second signal is received while the first signal is still being received, the controller stores the second signal in memory, and carries out the event, triggered by the second trigger signal only after the first trigger signal has stopped. The flush will operate after the solenoid closes for the length of time set or until another signal is received. At any one time, only a single solenoid may be operated, which ensures accuracy of dilution of the dosed chemical, as well as preventing dynamic water pressure from dropping to a point where the eductor no longer operates. An example of a control system 300 in accordance with the present invention is shown in particular in Figure 3. The operation of the control system 300 is similar to that described above with reference to Figures 1 and 2. As can be seen, the control system 300 comprises a dosing module 302 configured to activate, via wires 303, the dosing units 104 of the dosing apparatus 102. The control system 300 further comprises a flush module 304 configured to activate, via wire 305, the flush fluid unit 200 of the dosing apparatus 102. A storage module 306 is provided to store the above mentioned formulas. The trigger module 308 is electrically coupled to the trigger outputs of the laundry machine 310 by wires 312.

Upon receipt of a trigger signal, the corresponding formula is retrieved from the storage module 306. The delay module 314 analyses the formula to determine whether there is a delay time between activation of a first one of the dosing units 104, and a second one of the dosing units 104. Upon determining that there is a delay time, the delay time is compared to a predetermined threshold value. If the delay time exceeds the predetermined threshold time, a flush operation is activated after the first one of the dosing units has completed the dosing operation, but before the second one of the dosing units is activated. This enables the first chemical to be flushed through to the laundry machine where otherwise it would remain in the supply tube 316. In this particular example, the predetermined threshold is set at 39 seconds which has been found to advantageously reduce the risk associated with chemicals remaining in the supply tubing, but without over-using the flush fluid unit 200, and in particular the solenoid valve associated with that flush fluid unit.

In alternative examples, the predetermined threshold may be dependent on the chemicals being used, and the sequence of those chemicals in the formula. For example, if two chemicals must not mix within the supply tubing 316, then the predetermined threshold may be shorter.

The flush time may be between about 2 seconds and about 999 seconds. However, in some examples it may be between about 2 seconds and about 300 seconds, and in other examples between about 2 seconds and about 100 seconds.

In some circumstances, the delay time may be less than the flush time. In this case, the delay module can be configured to control the flush module to activate the flush fluid unit substantially constantly during the delay between the end of the activation of the first one of the at least two fluid dosing units, and the start of the activation of the second one of the at least two fluid dosing units.

As will be appreciated, the delay module analyses each delay within the formula, and activates the flush module for each delay which exceeds the threshold time. As discussed above, the threshold value used may be different depending on the type of chemical being dispensed, either when considered alone, or in combination with the second chemical to be dosed. In this case, the thresholds may be stored in a look-up table or the like, each threshold being associated with the chemical, or pair of chemicals.

The controller may comprise a display configured to display a timeline of the activation times, delay times, and whether or not an intermediate flush will be triggered.

A further example of a control system 400 will now be described with reference to figures 4 and 5. Like reference numerals refer to like features and components. As can be seen, the control system is configured to control the dosing apparatus 102 as described above, which supplies the laundry machine 310 with liquid cleaning chemicals via supply tubing 316. Again as described above, during normal use the laundry machine provides trigger signals to the controller via wires 312. The control system 400 is configured to enable a maintenance mode to be entered which prevents the trigger signals from activating the dosing apparatus.

The control system 400 thus comprises, inter alia, an input module 402 configured to receive an input from a user; a power module 404 configured to, upon activation by a user input, electrically isolate, using isolator 406 each of the fluid dosing units and the flush fluid unit from the trigger signal. The input module is configured to: receive an input from a user indicating that the power module should be activated to effect the electrical isolation; and send a corresponding signal to the power module. As will be appreciated, the control system may incorporate all of some of the features of control system 300 described above.

Advantageously, providing such a power module and input module enables the control system to be isolated from any trigger signals, initiated by the laundry machine 310 being supplied by the fluid dosing apparatus 102. In particular, upon the equipment being maintained, the maintenance operative provides the input to the control system to activate the power module and electrically isolate the dosing units and flush unit from any trigger signals that may be sent by the equipment during maintenance. In this way, the safety of the system is improved.

The input module is further configured to: receive an input from the user indicating that the power module should be deactivated; and send a corresponding signal to the power module. The input module may comprise a code sub-module configured to receive a deactivation code from the user. In this way, the control system may not be reactivated until a reactivation code is received. The control system may have an indicator, configured to indicate to a user upon the power module being activated. The indicator may be visual, or audible. The visual indicator may flash, or be constant. The indicator may be configured to issue an audible indication upon receipt of a trigger signal. In this way, advantageously, the user is made aware that a trigger signal was received from the equipment. In this scenario, either the received signal was a stray trigger signal caused by the maintenance, or the user did not deactivate the power module after completing the maintenance operation.

Figure 5 shows the portion of the control menu user interface 500 of the control system 400. As can be seen, the maintenance mode 502 is one of a plurality of options available to the user.

A further example of a control system 600 will now be described with reference to figures 6, 7, 8 and 9. Like reference numerals refer to like features and components. As can be seen, the control system is configured to control the dosing apparatus 102 as described above, which supplies the laundry machine 310 with liquid cleaning chemicals via supply tubing 316. Again as described above, during normal use the laundry machine provides trigger signals to the controller via wires 312. The control system 600 is configured to enable passcode controlled access to the features and reports stored in the controller.

The control system 600 comprises: a storage module 602 for storing: a plurality of settings, the settings being at least one of: a duration of activation of one of the at least two dosing units; a duration of activation of the flush fluid unit; an order of activation of the at least two dosing units; and at least one delay time between activation of the at least two dosing units; and a usage report comprising an activation count for each of the at least two dosing units. The control system 600 further comprises an access module 604, configured to receive a first access code to enable access to all of the plurality of settings and the usage report, and a second access code to enable access only to the usage report.

Advantageously, providing such a system enables a low-level user to access a usage report without providing full access to the settings of the control system. In this way, the low- level user is prevented from changing the settings of the control system.

To enable the low-level user to review the usage report their access code provides access to, a port 606 is provided (also shown in Figure 1 ) to enable removable storage 608 to be connected to the controller. For example, the port 606 may be a USB port, the removable storage 608 being a USB memory stick, or the like. Upon the user inserting the removable storage 608, the access module prompts the user to enter their access code. If the access code is associated with a low-level user, only access to a predetermined subset of features is enabled. In one example, shown in Figure 7, the user is prompted to respond by inputting whether a usage report is required. If so, the start date and end date for the report is requested, a title for the report is also requested. After which the usage report is downloaded to the removable storage 608 for future review. An example of such a usage report is shown in Figure 8. Figure 9 shows a user interface menu for enabling and setting the second access code. The storage module 602 of the control system 600 may be further configured to store a plurality of reports, including at least one usage report and at least one of: a set-up report; and an event report. The access module is further configured to enable access to all of the plurality of settings and all of the plurality of reports upon receipt of the first access code. The second access code may only enable access to a subset of those reports.