Time scheduling method and scheduler for a modular engine that negotiates among modules timing offers which include a timing range

• US 6,633,990 B1
• Filed: 03/15/2000
• Issued: 10/14/2003
• Est. Priority Date: 03/15/1999
• Status: Expired due to Term

• Current Assignee: Océ-Technologies B.V. (Canon Inc.)
• Original Assignee: Océ-Technologies B.V. (Canon Inc.)
• Inventors: Eisenberg, Rolf
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): WANG, ALBERT C
• Application Number:
  US09/525,947
• Time in Patent Office: 1,308 Days
• Field of Search: 355/133, 358/1.15, 358/296, 399/75, 706/10, 713/400
• US Class Current: 713/400
• CPC Class Codes: G05B 19/0426 Programming the control sequence

Abstract

Disclosed are a time scheduling method and scheduler for a modular engine, e.g. a sheet handling engine. Interaction between the modules (e.g., 12, 14, 16, 18) of the engine involves an output from one module being delivered as an input to another module. The engine has at least one module (e.g., 12) that does not need an input from another module for performing a first action. The method comprises the allocation of a time to each action to be performed by the modules on the basis of information on the current status and timing constraints of the respective modules, wherein each module allocates the timings for its own actions by sending a timing offer (e.g., F[OK, . . . , . . . ]) to the module to which the output has to be delivered and receiving from that module a message (e.g., B[OK, . . . ]; B[NOT OK, . . . ]) accepting or rejecting the offer. The timing offer is based on the internal status and timing constraints of the module itself and, if an input from another is needed, on a timing offer from that module.

Claims

1. A time scheduling method for a modular engine, said modular engine including a set of action modules for performing a particular action, respectively, wherein, for a chain of actions to be scheduled, interaction between the modules involved in said chain of actions is defined as an output from one module that is delivered as an input to another module, the engine having at least one module that does not need an input from another module for performing a first action, the method allocating a time to each action to be performed by the modules on the basis of information on the current status and timing constraints of the respective modules, the method comprising:

each action module allocating the timings for its own actions by sending a timing offer including a timing range to a recipient module to which said output of the action module has to be delivered; and

each module receiving from the corresponding recipient module a message accepting or rejecting the offer, respectively, a message accepting the offer including a specific interaction time selected from the timing range;

wherein the timing offer is based on the internal status and timing constraints of the module sending the timing offer, and if an input from another module is needed, on a timing offer from that other module.

2. The method according to claim 1, wherein a message rejecting a timing offer includes information on timings at which the interaction is not possible, and the action module receiving this messages sends another timing offer on the basis of that information.

3. The method according to claim 1, wherein, when a recipient module rejects a timing offer, all the other modules are instructed to abort the scheduling process and to wait for an instruction concerning a new scheduling attempt.

4. The method according to claim 1, wherein, when a module involved in a particular chain of actions to be scheduled takes an inoperative status for unpredictable time period, all the other modules involved are instructed to abort the scheduling process, and a new scheduling process for said particular chain of actions is started only after the module that has been inoperative sends a signal indicating that it is operative again.

5. The method according to claim 1, wherein all the modules report to an engine controller whether or not the scheduling process has been successful and, in case of success, the modules report the timings that have been allocated to its actions.

6. The method according to claim 1, wherein the modules of an engine and the interactions therebetween define a loop, and wherein a module, at which a first input returned from the loop is combined with a second input entering into the loop from a preceding module, reacts to a timing offer from the module that returns the input from the loop by sending a message to said preceding module, whereupon the preceding module sends a timing offer for the second input.

7. A scheduler system for a modular engine having multiple modules, the scheduler system comprising:

a plurality of control units respectively associated with the multiple modules,

each control unit being operable to at least detect or store an internal status and the timing constraints of the associated module and to send a timing offer including a timing range to the control unit of the module to which the input is to be sent,

wherein each control unit is further operable to check whether a timing offer received from another module is compatible with its own status and timing constraints, and with timing offers received from other modules, and to send a message accepting or rejecting the timing offer back to the other module from which the timing offer has been sent, a message accepting the offer including a specific interaction time selected from the timing range.

8. The scheduler system according to claim 7, wherein the control units are formed by separate processors that are linked together by a bus system.

9. The scheduler system according to claim 7, wherein the modular engine is a modular sheet handling engine.

10. The scheduler system according to claim 9, wherein the multiple modules include an engine controller module, a paper input module, an image provider module, a process module and a paper output module.

11. The scheduler system according to claim 10, wherein the multiple modules include a duplex switch module and a duplex loop module for handling duplex copies.