MASTER COMMUNICATION DEVICE FOR A TOKEN NETWORK

Abstract

Master communication device for a token network. The token network comprises a shared communication medium and at least one further master communication device coupled to the shared communication medium, the token network being arranged to pass frames and to execute a poll for master cycle. The master communication device is restricted in executing a poll for master cycle in specified cases especially if another device executed a poll for master for finding a new master communication device on the token network.

Claims

1. Master communication device for a token network, the token network comprising a shared communication medium and at least one further master communication device coupled to the shared communication medium, the token network having a master token chain providing a logic order of master communication devices in the token network, the token network being arranged to pass a master token along the master token chain and to pass frames and to execute a poll for master cycle, a next master communication device being downstream from the master communication device in the master token chain, a previous master communication device being upstream from the master communication device in the master token chain, the master communication device comprising: a pass unit arranged to pass the master token to the next master communication device and set the master communication device in a listening state when passing the master token; an accept unit arranged to accept the master token from the previous master communication device and set the master communication device in a transmission state when accepting the master token; and a poll for master unit arranged to execute the poll for master cycle if the master communication device is in the transmission state, the poll for master cycle comprising at least one transmission of a poll for master frame to the token network, the poll for master unit being arranged to restrict said execution of the poll for master cycle when at least one poll for master frame was present on the shared medium during that the master communication device was in the listening state preceding the transmission state.

2. Master communication device according to claim 1, comprising a master token counter to hold a master token counter value, the accept unit being arranged to increase the master token counter value when the accept unit accepts the master token; the poll for master unit being further arranged to restrict said execution of a poll for master when the master token counter value is lower than a master token count threshold; and the poll for master unit being arranged to reset the master token counter value after the poll for master cycle was executed.

3. Master communication device according to claim 1, comprising a detect unit arranged to detect a poll for master frame on the shared medium originating from a further master communication device if the master communication device is in the listening state.

4. Master communication device according to claim 3, the detect unit being arranged to decrease the master token counter value when the detect unit detects the poll for master frame.

5. Master communication device according to claim 3, comprising a poll for master skip flag; the pass unit being arranged to reset the poll for master skip flag when the pass unit passes the master token; the detect unit being arranged to set the poll for master skip flag when the detect unit detects the poll for master frame; and the poll for master unit being further arranged to restrict the poll for master cycle when the poll for master skip flag is set.

6. Master communication device according to claim 1, comprising a poll for master token flag; the accept unit being further arranged to set the poll for master token flag when the accept unit accepts a poll for master token from the shared medium; the poll for master unit being further arranged to restrict the poll for master cycle when the poll for master token flag is not set; and the pass unit being further arranged to reset the poll for master token flag when the pass unit passes the poll for master token to the shared medium destined for a further master communication device.

7. Master communication device according to claim 6; the pass unit being arranged to pass the poll for master token and the master token in a single frame; and the accept unit being arranged to accept the poll for master token and the master token in a single frame.

8. Master communication device according to claim 6; the pass unit being arranged to pass the poll for master token and the master token in separate frames; and the accept unit being arranged to accept the poll for master token and the master token in the separate frames.

9. Master communication device according to claim 1, the poll for master unit being arranged to split a poll for master cycle over a plurality of periods the master communication device is in the transmission state.

10. Master communication device according to claim 1, the master communication device being a BACnet MS/TP master network node.

11. Method for a poll for master cycle for a token network comprising a shared communication medium and at least one further master communication device coupled to the shared communication medium, the token network having a master token chain providing a logic order of master communication devices in the token network, the token network being arranged to pass a master token along the master token chain and to pass frames, a next master communication device being downstream from the master communication device in the master token chain, a previous master communication device being upstream from the master communication device in the master token chain, wherein the method comprises the steps of: passing a master token to the next master communication device on the token network by a master communication device on the token network and thereby setting the master communication device in a listening state; accepting the master token from the previous master communication device on the token network by the master communication device and thereby setting the master communication device in a transmission state; and executing the poll for master cycle if the master communication device is in the transmission state, the poll for master cycle comprising at least one transmission of a poll for master frame to the token network, the poll for master unit being arranged to restrict said execution of the poll for master cycle when at least one poll for master frame was present on the shared medium in the listening state preceding the transmission state.

12. Integrated circuit device comprising a master communication device according to claim 1.

13. Computer program product for a processor arranged to a master communication device according to claim 1 or arranged to an integrated circuit device, which program is operative to cause the processor to perform the functions of the mentioned claims, or a processor arranged for execution.

14. A non-transitory tangible computer readable storage medium comprising data loadable in a programmable apparatus arranged to a master communication device or an integrated circuit device, which data representing instructions executable by the programmable apparatus, the instructions comprising one or more and partly or whole the functions or a programmable apparatus arranged for execution of the method of claim 11, the data representing instructions executable by the programmable apparatus.

15. Token network having a shared medium and arranged to execute a poll for master cycle comprising a plurality of master communication devices according to claim 1; at least one master communication device operating and at least one further master communication device; or at least one integrated circuit device coupled to the token network and at least one further master communication device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0063] These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of example in the following description and with reference to the accompanying drawings, in which

[0064] FIG. 1 schematically shows an example of an embodiment of a trunk control network for a lighting system.

[0065] FIG. 2 schematically shows an example of an embodiment of a master communication device and a token network.

[0066] FIG. 3 schematically shows an example of an embodiment of a master communication device having a detect unit and a token network.

[0067] FIG. 4 schematically shows an example of an embodiment of a flowchart of a first embodiment.

[0068] FIG. 5 schematically shows an example of an embodiment of a flowchart of a second embodiment.

[0069] FIG. 6 schematically shows an example of an embodiment of a flowchart of a third embodiment.

[0070] FIG. 7 schematically shows an example of an embodiment of a flowchart of a fourth embodiment.

[0071] FIG. 8 schematically shows a block diagram of an integrated circuit device.

[0072] FIG. 9 schematically shows an example of an embodiment of a computer program product and/or non-transitory computer readable storage medium.

[0073] FIG. 10 schematically shows an example of an embodiment of a token network.

[0074] FIG. 11 schematically shows an example of state diagram of an embodiment of a token network.

[0075] The figures are purely diagrammatic and not drawn to scale. In the Figures, elements which correspond to elements already described may have the same reference numerals.

List of Abbreviations:

[0076] LSt Listening State

[0077] MAC Medium Access Control

[0078] MCD Master Communication Device

[0079] MT Master Token

[0080] MTC Master Token Counter

[0081] MTCV Master Token Counter Value

[0082] NS Next Station i.e. Next master communication device

[0083] PFM Poll For Master

[0084] PFMF Poll For Master Flag

[0085] PFMT Poll For Master Token

[0086] Rx Receive

[0087] SCD Slave Communication Device

[0088] PFM SF Poll For Master Skip Flag

[0089] TN Token Network

[0090] TS This Station i.e. Current master communication device

[0091] TSt Transmission State

[0092] Tx Transmit

List of Reference Numerals:

[0093] 1, 1 Token network

[0094] 2, 2 Shared medium

[0095] 3 Aggregating communication network

[0096] 4 Network node with luminaire

[0097] 5 Network node with sensor

[0098] 6 Network node with luminaire and sensor

[0099] 7 Network router node

[0100] 10 Trunk control network

[0101] 100 Master Communication Device

[0102] 101 Pass unit

[0103] 102 Detect unit

[0104] 103 Accept unit

[0105] 104 Poll for master unit

[0106] 105 Device State unit

[0107] 110 To Listening signal

[0108] 111 To Transmission signal

[0109] 112 PFM Prevent signal

[0110] 113 Current State signal

[0111] 120 Pass MT signal

[0112] 121 Rx Frame signal

[0113] 122 Accept MT signal

[0114] 123 PFM Action signal

[0115] 151 Shared medium

[0116] 152 Coupling between shared medium and master communication device

[0117] 200 Flowchart first embodiment

[0118] 201,301,401,501 Start

[0119] 402 Reset PFM SF

[0120] 203, 303, 403 Listen to the TN

[0121] 204, 304, 404 Increment MTCV

[0122] 205, 305, 405, 505 Transmission of data

[0123] 406 Check if PFM SF is set

[0124] 307 Check if PFMT was received

[0125] 208, 308, 408 Check if MTCVNpoll

[0126] 209, 309, 409 Check if NS-TS-1=0

[0127] 210, 310, 410 Perform PFM cycle

[0128] 211, 311, 411 Check if PFM cycle is completed

[0129] 212, 312, 412 Set MTCV to 0

[0130] 224, 324, 424 End

[0131] 313 Reset PFMF

[0132] 314 Check if PFMF is set

[0133] 316 Set PFMF

[0134] 220 Set MTCV to 0

[0135] 221, 321, 421 Pass MT to TN

[0136] 322 Pass MT and PFMT to TN

[0137] 300 Flowchart second embodiment

[0138] 400 Flowchart third embodiment

[0139] 420 Set PFM SF

[0140] 500 Flowchart fourth embodiment

[0141] 530 Pass MT

[0142] 531 Detect PFMF

[0143] 532 Accept MT

[0144] 533 Check PFM detected

[0145] 534 Possible PFM cycle

[0146] 600 Integrated Circuit Device

[0147] 610 Integrated Circuit Die

[0148] 620 Master Communication Device

[0149] 622, 624, 626 Further devices

[0150] 630 Coupling device

[0151] 700 Computer Program Product and/or Non-transitory Computer

[0152] Readable Storage Medium

[0153] 710 Writeable part

[0154] 720 Computer Program

[0155] 800 Token Network

[0156] 801, 801 Master Communication Device

[0157] 802 Master Communication Device/Slave Communication Device

[0158] combination

[0159] 803 Slave Communication Device

[0160] 810, 810, 810, 810 Communication coupling

[0161] 811 Shared Medium

[0162] 900 State diagram of a master communication device

[0163] 910, 910, 910 TSt, Transmission state

[0164] 911 Transmission state period

[0165] 920, 920, 920 LSt, Listening state

[0166] 930 Progress of time

DETAILED DESCRIPTION OF EMBODIMENTS

[0167] While this invention is susceptible of embodiment in many different forms, there are shown in the drawings and will herein be described in detail one or more specific embodiments, with the understanding that the present disclosure is to be considered as exemplary of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described.

[0168] In the following, for the sake of understanding, elements of embodiments are described in operation. However, it will be apparent that the respective elements are arranged to perform the functions being described as performed by them.

[0169] FIG. 1 schematically shows a trunk control network 10 for a lighting system. The trunk control network comprises an aggregating network 3, a first token network 1, 1, 1 and a second token network 2, 2, 2. The first and second token network are coupled to the aggregating network by respective edge routers 7 for allowing access to and from the token network to other networks coupled to the aggregating network. FIG. 1 shows an example of a lighting network application of the token network. The first token network therefore comprises parts of the lighting system, which are all optional. The first token network in the example comprises the edge router, a luminaire 4, a sensor 5 and a luminaire-sensor combination 6. The luminaire can be implemented as slave communication device. The sensor can be implemented as master communication device. The edge router can be implemented as master communication device. The luminaire-sensor combination can be implemented as master/slave communication device.

[0170] The aggregating network of FIG. 1 aggregates the separate token networks to let the two token networks share information as well as to make the token networks accessible to the outside world.

[0171] The token network comprises a master token, which is handed from master communication device to master communication device to allow masters on the token network to take the initiative to start a transmission and thereby the exchange of information.

[0172] FIG. 2 schematically shows a master communication device 100 and a token network 150. The token network comprises a shared medium 151 and a coupling 152 coupling the shared medium and the master communication device.

[0173] The master communication device comprises a pass unit 101, an accept unit 103, a poll for master unit 104 and a device state unit 105. The pass unit passes a master token 120 to the token network. The accept unit accepts master tokens 122 from the token network. The poll for master unit performs PFM actions 123 on the token network.

[0174] In the device state unit a current state is kept. The current state can be a listening state or a transmission state. The pass unit sets the device state unit in the listening state 110 when the master token is passed to the token network. The accept unit sets the device state unit in the transmission state 111 when the master token is accepted from the token network. The poll for master unit is provided with the current state. The poll for master unit is restricted from executing a PFM action or limited in the amount of PFM actions during the time the current state is the transmission state and at least one PFM action was present in the listening state preceding the current transmission state.

[0175] FIG. 3 schematically shows a further master communication device 100 and a token network 150. The master communication device of FIG. 3 comprises a detect unit and a poll for master unit 104 with an additional input. The detect unit is provided with the current state 113. The detect unit filters the received frames and sets the PFM prevent signal 112 during that the current state is next time in the transmission state when the current state is the listening state and a poll for master frame was detected.

[0176] The poll for master unit is provided with the current state and the PFM prevent signal. The poll for master unit 104 is allowed to start a poll for master during the time the current state is the transmission state and the PFM prevent signal is absent.

[0177] FIG. 4 schematically shows a flowchart of a first embodiment 200 having a reset of a Master Token Counter Value (MTCV). From a start 201 the master communication device starts listening to the bus 203. If during listening a PFM frame not destined for the current master communication device is received the MTCV is set to zero 220 and listening to the token network 203 is continued. If during listening a master token is received the MTCV is incremented 204 and next, if there is data available at the master for transmission then that data is transmitted 205 from the master to at least one other device on the network. After data transmission a check is performed if the MTCV is equal or higher than the Npoll value 208. If no then the master token is passed 221 to the token network. If yes then a following check is performed if a network address range is assigned to the master communication device 209 by checking the network address of the master communication device and the network address of the next master communication on the token network. If no network address range was assigned (indicated as Y) then the master token is passed 221 to the token network. If a network address range was assigned (indicated as N) a PFM action 210 is performed. After the PFM action a check is performed if a PFM cycle is completed 211. If the PFM cycle was not completed then the master token is passed 221 to the token network. If the PFM cycle was completed then the MTCV is set to zero 212 where after the master token is passed 221 to the token network. If the master token is passed to the shared medium destined to a next master communication device, the end 224 state is reached.

[0178] In the event that a PFM frame was present on the shared medium the response time may be increased. To reduce any further increase of a response time or even exceeding a maximum response time a MTCV of a master communication device is set to zero by the master communication device executing the flowchart of FIG. 4. This set causes the master communication device to not be able to execute a PFM action during the following transmission state of the master communication device.

[0179] FIG. 5 schematically shows a flowchart of a second embodiment 300 having a Poll For Master Token (PFMT). From a start 301 the master communication device starts listening to the bus 303. If during listening a master token was received the MTCV is incremented 304 where after if there is data available at the master for transmission the data is transmitted 305 from the master to at least one other device on the network. After data transmission a check is performed if the PFMT was received 307. If the PFMT was not received then a check is performed if the PFMF is set 314. If the PFMF is not set then the master token is passed 321 to the token network. If the PFMF is set then a PFM action is performed 310.

[0180] If the PFMT was received then a check is performed if the MTCV is equal or higher than the Npoll value 308. If no then the master token and the PFMT are passed 322 to the token network. If yes then a following check is performed if a network address range is assigned to the master communication device 309 by checking the network address of the master communication device and the network address of the next master communication on the token network. If no network address range was assigned (indicated as Y) then the master token and the PFMT are passed 322 to the token network. If a network address range was assigned (indicated as N) the PFM action 310 is performed. After the PFM action a check is performed if a PFM cycle is completed 311. If the PFM cycle is not completed then the PFMF is set where after the master token is passed 321 to the token network. If the PFM cycle is completed then the MTCV is set to zero 312 and the PFMF is reset 313 where after the master token is passed 321 to the token network. If the master token is passed or the master token and poll for master token are passed to the shared medium destined to a next master communication device, the end 324 state is reached.

[0181] To reduce any further increase of a response time or even exceeding a maximum response time a PFMT is passed between master communication devices. The PFMT may prevent multiple masters to execute a PFM action in the same time frame as seen for a response time of a master communication device.

[0182] FIG. 6 schematically shows a flowchart of a third embodiment 400 having a Poll For Master Skip Flag (PFM SF). From a start 401 the master communication device resets the PFM SF 402 where after the master communication device starts listening to the bus 403. If during listening a PFM frame is received the PFM SF is set 420 and listening to the token network 403 is continued. If during listening a master token is received the MTCV is incremented 404 and if there is data available at the master for transmission then that data is transmitted 405 from the master to at least one other device on the network.

[0183] After data transmission a check is performed if the PFM SF is set. If the PFM set is set then the master token is passed 421 to the token network. If the PFM SF is not set then a check is performed if the MTCV is equal or higher than the Npoll value 408. If no then the master token is passed 421 to the token network. If yes then a following check is performed if a network address range is assigned to the master communication device 409 by checking the network address of the master communication device and the network address of the next master communication on the token network. If no network address range was assigned (indicated as Y) then the master token is passed 421 to the token network. If a network address range was assigned (indicated as N) a PFM cycle 410 is performed. After the PFM cycle a check is performed if a PFM cycle is completed 411. If the PFM cycle was not completed then the master token is passed 421 to the token network. If the PFM cycle was completed then the MTCV is set to zero 412 where after the master token is passed 421 to the token network. If the master token is passed to the shared medium destined to a next master communication device, the end 424 state is reached.

[0184] In the event that a PFM frame was present on the shared medium the response time may be increased. To reduce any further increase of a response time or even exceeding a maximum response time a PFM SF of a master communication device is set by the master communication device executing the flowchart of FIG. 6. This set causes the master communication device to not be able to execute a PFM action during the following transmission state of the master communication device.

[0185] FIG. 7 schematically shows an example of an embodiment of a flowchart of a fourth embodiment 500. From a start 501 a master communication device passes a MT 530 to a token network. After passing the master communication device listens to the token network and detects if a PFM is present. If during listening the MT is received by the master communication device the master communication device accepts the MT 532. After accepting any data to be transmitted is transmitted 505. If there is data available for transmission at the master then that data is transmitted and a check is done if a PFM was received during the previous period the master communication device was not having the MT 533. If yes then the MT is passed 530 and the flowchart starts at the beginning If no then the master communication device may decide to perform a PFM cycle or part of a PFM cycle 534, such as one PFM action. After performing a PFM cycle or part of a PFM cycle the MT is passed to the token network 530 and the flowchart starts at the beginning

[0186] In the event that a PFM frame was present on the shared medium the response time may be increased. To reduce any further increase of a response time or even exceeding a maximum response time a master communication device restricted in executing a PFM action as shown in FIG. 7. This restriction of the master communication device causes the master communication device to not be able to execute a PFM action during the following transmission state of the master communication device.

[0187] FIG. 8 schematically shows a block diagram of an integrated circuit device 600. The integrated circuit device comprises an integrated circuit die 610. The integrated circuit die comprises at least a master communication device 620 and several optional devices 622, 624, 626 and at least in case of one or more optional devices a coupling device 630. The coupling device electrically couples the master communication device with the several optional devices for communication between the devices.

[0188] FIG. 9 schematically shows an example of an embodiment of a computer program product, computer readable medium and/or non-transitory computer readable storage medium 700 having a writable part 710 comprising a computer program 720, the computer program comprising instructions for causing a processor system to perform a method of an embodiment. The computer program may be embodied on the computer readable medium as physical marks or by means of magnetization of the computer readable medium. However, any other suitable embodiment is conceivable as well. Furthermore, it will be appreciated that, although the computer readable medium 700 is shown here as an optical disc, the computer readable medium 700 may be any suitable computer readable medium, such as a hard disk, solid state memory, flash memory, etc., and may be non-recordable or recordable. The computer program comprises instructions for causing a processor system to perform said method of an embodiment.

[0189] FIG. 10 schematically shows an example of an embodiment of token network 800. The token network comprises a shared medium 811 and several optional devices 801, 801, 802, 803 according to embodiments coupled 810, 810, 810, 810 to the token network.

[0190] Many different ways of executing the method are possible, as will be apparent to a person skilled in the art. For example, the order of the steps can be varied or some steps may be executed in parallel. Moreover, in between steps other method steps may be inserted. The inserted steps may represent refinements of the method such as described herein, or may be unrelated to the method. For example, a given step may not have finished completely before a next step is started.

[0191] FIG. 11 schematically shows an example of state diagram 900 of an embodiment of token network. The state diagram comprises the transmission state (TSt) 910, 910, 910 and the listening state (LSt) 920, 920, 920. The state diagram shows further the progress of time direction 930. For the transmission state 910 the preceding listening state 920 is directly before this transmission state seen in the time. For the transmission state 910 the next listening state 920 is directly after this transmission state seen in the time. A transmission state period 911 is defined as the continuous period in time a master communication device is in the transmission state.

[0192] Master communication device for a token network. The token network comprises a shared communication medium and at least one further master communication device coupled to the shared communication medium, the token network being arranged to pass frames and to execute a poll for master cycle. The master communication device is restricted in executing a poll for master cycle in specified cases especially if another device executed a poll for master for finding a new master communication device on the token network.

[0193] It will be appreciated that the above description for clarity has described embodiments of the invention with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units or processors may be used without deviating from the invention. For example, functionality illustrated to be performed by separate units, processors or controllers may be performed by the same processor or controllers. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality rather than indicative of a strict logical or physical structure or organization. The invention can be implemented in any suitable form including hardware, software, firmware or any combination of these.

[0194] It is noted, that in this document the word comprising does not exclude the presence of other elements or steps than those listed and the word a or an preceding an element does not exclude the presence of a plurality of such elements, that any reference signs do not limit the scope of the claims, that the invention may be implemented by means of both hardware and software, and that several means or units may be represented by the same item of hardware or software, and a processor may fulfill the function of one or more units, possibly in cooperation with hardware elements. Further, the invention is not limited to the embodiments, and the invention lies in each and every novel feature or combination of features described above or recited in mutually different dependent claims.