Devices, systems, and methods for assigning a PLC module address

• US 8,321,653 B2
• Filed: 08/08/2007
• Issued: 11/27/2012
• Est. Priority Date: 08/08/2006
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: McNutt, Alan D., Boggs, Mark Steven, Fulton, Temple L.
• Primary Examiner(s): NGUYEN, TANH Q
• Application Number:
  US11/891,002
• Publication Number:
  US 20080091931A1
• Time in Patent Office: 1,938 Days
• Field of Search: None
• US Class Current: 713/1
• CPC Class Codes: G05B 19/054 Input/output
• CPC Class Codes: G05B 2219/1109 Expansion, extension of I-O
• CPC Class Codes: G05B 2219/1113 Address setting
• CPC Class Codes: G05B 2219/15072 Modules in daisy chain, connected by parallel cable
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 25/4908 using mBnB codes

Abstract

Certain exemplary embodiments can comprise a system, which can comprise a module communicatively coupled to a programmable logic controller (PLC). The module can comprise a transmission circuit and/or a receiving circuit. The module can be adapted to communicate with the PLC via 8B/10B encoded frames. A frame of the 8B/10B encoded frames can comprise a plurality of ordered fields.

Claims

1. A memory comprising machine instructions for activities comprising:

sending a first message from a programmable logic controller (PLC) to a module, said first message transmitted via a first 8B/10B encoded frame that comprises a destination address that is an eight bit default module address of said module, said first message adapted to change a module address of said module from said default module address to an assigned address value and if the module address has been changed, adapted to cause said module to transmit a reply message to the PLC via a second 8B/10B encoded frame, the reply message comprising source address that confirms said assigned address value has been assigned to said module by said first message, said first 8B/10B encoded frame comprising a message type field of a size of eight bits, a value stored in said message type field indicative of content of a data field of said first 8B/10B encoded frame, said message type field following a first ordered sequence of fields comprised by said first 8B/10B encoded frame, said first ordered sequence of fields comprising a preamble field, a start-of-frame field, a destination address field of a size of eight bits, a length field, and a source address field of a size of eight bits, said message type field followed by a second ordered sequence of fields comprised by said first 8B/10B encoded frame, said second ordered sequence comprising a data field, a cyclic redundancy check field of a size of 32 bits, and an end of frame field;

responsive to a failure to receive said reply message via said second 8B/10B encoded frame, receiving at the PLC a response to said first message, said response comprised by a third 8B/10B encoded frame, said third 8B/10B encoded frame comprising an error code field that contains a value indicative of an error condition associated with the first message;

the PLC automatically performing at least one of interpreting, reporting and taking corrective action in response to the value indicative of the error condition associated with the first message contained in the error code field;

responsive to a failure to receive said reply message at the PLC, sending a second message via a fourth 8B/10B encoded frame to said module, said second message adapted to set said module address to said default eight bit module address;

responsive to said second message adapted to set said module address to said default eight bit module address, receiving at the PLC a response message from the module via a fifth 8B/10B encoded frame, said response message adapted to confirm that said module address has been reset to said default eight bit module address;

responsive to said second message adapted to set said module address to said default eight bit module address, sending a third message from the PLC via a sixth 8B/10B encoded frame to said module, said third message adapted to change a module address of said module from said default module address to an assigned address value;

responsive to said third message, receiving at the PLC a response message via a seventh 8B/10B encoded frame, said response message adapted to confirm that said assigned address value has been assigned to said module by said third message;

sending a fourth message from the PLC via a eighth 8B/10B encoded frame to said module, said fourth message adapted to cause said module to enable communications with a communicatively coupled second module and for the module to send a confirming message to the PLC acknowledging receipt and action in response to said third message;

responsive to the fourth message, receiving at the PLC said confirming message via a ninth 8B/10B encoded frame.