Controller

• US 6,449,515 B2
• Filed: 02/05/2001
• Issued: 09/10/2002
• Est. Priority Date: 11/29/1996
• Status: Expired due to Term

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Imoto, Masaru
• Primary Examiner(s): Picard, Leo
• Assistant Examiner(s): Garland, Steven R.
• Application Number:
  US09/775,563
• Publication Number:
  US 20010053619A1
• Time in Patent Office: 582 Days
• Field of Search: 700/11-27, 700/86, 700/89, 710/1, 712/37, 711/115
• US Class Current: 700/23
• CPC Class Codes: G05B 19/0423 Input/output
• CPC Class Codes: G05B 19/05 Programmable logic controllers, e.g. simulating logic interconnections of signals according to ladder diagrams or function charts
• CPC Class Codes: H05K 7/1428 for small modular apparatus with terminal block
• CPC Class Codes: H05K 7/1468 Mechanical features of input/output (I/O) modules
• CPC Class Codes: H05K 7/1479 including decentralized modules, e.g. connected to other modules using fieldbus
• CPC Class Codes: H05K 7/1481 User interface, e.g. status displays; Programming interface, e.g. connector for computer programming; Monitoring
• CPC Class Codes: H05K 7/1484 Electrical diagrams relating to constructional features, e.g. signal routing within PLC; Provisions for disaster recovery, e.g. redundant systems

Abstract

A programmable controller includes a terminal which receives input data from an input unit and outputs output data to be applied to an output unit. The programmable controller also includes a communication unit which executes a serial communication with the terminal to send the output data to the output unit and to receive the input data from the input unit. A control unit repeatedly executes an input process for reading the input data received by the communication unit, an output process for sending the output data to be transmitted by the communication unit, a program execution process for executing a user program and an other process. The program execution process is executed between the input process and a subsequent output process, and the other process is executed between the output process and a subsequent input process.

Claims

1. A programmable controller, comprising:

a terminal which receives input data from an input unit and outputs output data to be applied to an output unit;

a communication unit, coupled to the terminal, which executes a serial communication with the terminal to send the output data to the output unit and to receive the input data from the input unit; and

a control unit which repeatedly executes an input process for reading the input data received by the communication unit, an output process for sending the output data to be transmitted by the communication unit, a program execution process for executing a user program and an other process, the program execution process being executed between the input process and a subsequent output process and the other process being executed between the output process and a subsequent input process.

2. A programmable controller according to claim 1, wherein a communication cycle of the communication unit starts with the sending of the output data by the communication unit.

3. A programmable controller according to claim 1, wherein a communication cycle of the communication unit starts with the sending of the output data by the communication unit and ends by the receipt of the input data by the communication unit following the sending.