Industrial wireless network

• US 20050018643A1
• Filed: 05/28/2004
• Published: 01/27/2005
• Est. Priority Date: 05/30/2003
• Status: Abandoned Application

• Current Assignee: Adaptive Instruments Corporation (Schneider Electric SE)
• Original Assignee: Adaptive Instruments Corporation (Schneider Electric SE)
• Inventors: Neilson, Paul, Sanford, John, Schumacher, Justin
• Application Number:
  US10/856,349
• Publication Number:
  US 20050018643A1
• Time in Patent Office: Days
• US Class Current: 370/347
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A system for wirelessly communicating between multiple devices of a process control system is disclosed. The system includes a basestation that communicates with multiple field units via a wireless signal and in accordance with a wireless protocol. The wireless protocol is made up of frames that are defined by multiple time slots, an initial one of which is reserved for a wireless start-frame message from the basestation to multiple field units. The base station utilizes the start-frame message to assign the remaining time slots to field units and to provide information to synchronizing the field units to the basestation.

Claims

1. A process control and monitoring system for wirelessly communicating with multiple devices, the system comprising:

a. a basestation that communicates with multiple field units via a wireless signal and in accordance with a wireless protocol;

b. multiple field units that receive wireless signals in accordance with the wireless protocol from the basestation and respond to requests from the basestation via wireless signals in accordance with the wireless protocol; and

c. wherein the wireless protocol includes frames defined by multiple time slots including,

i. an initial time slot reserved for a wireless start-frame message from the basestation to multiple field units, the wireless start-frame message from the basestation assigning the remaining time slots to field units, and providing information for synchronizing the basestation and the field units, and

ii. a later time slot reserved for a wireless message from a field unit to the basestation.

2. The system of claim 1, wherein the wireless start-frame message has a header portion, a data portion, and an error detection and correction portion.

3. The system of claim 1, wherein the start-frame wireless message contains information about the number of frames and the frame number.

4. The system of claim 1, wherein the wireless messages communicated by the basestation and the field units include unique identifiers.

5. The system of claim 1, wherein the wireless start-frame message from the basestation informs the field unit when their assigned time slot will occur.

6. The system of claim 1, wherein the frequency of the wireless signals used by the basestation and the field units are in the range of about 902 MHz to 928 MHz.

7. The system of claim 1, wherein additional communication between the basestation and the field units is in the form of wireless messages having a header portion, a data portion, and an error detection and correction portion.

8. The system of claim 7, wherein the header portion of the wireless messages from the basestation includes a unique identifier for indicating with which field unit the basestation is attempting to communicate.

9. The system of claim 7, wherein the field units are capable of sending data related to a manufacturing process to the basestation via the wireless messages when requested by the basestation.

10. The system of claim 1, wherein the field units are capable of controlling the parameters of a process when directed by the basestation via the wireless messages.

11. The system of claim 1, wherein the system includes multiple basestations.

12. The system of claim 11, wherein multiple basestations send and receive wireless messages from the field units during different time periods.

13. The system of claim 1, wherein the start-frame wireless message directs at least one of the field units to listen to future messages for data.

14. The system of claim 1, wherein the start-frame message acknowledges an earlier message sent by a field unit.

15. A process control and monitoring system for wirelessly communicating with multiple devices, the system comprising:

a. a basestation that communicates with multiple field units via a wireless signal and in accordance with a wireless protocol;

b. multiple field units that receive wireless signals in accordance with the wireless protocol from the basestation and respond to requests from the basestation via wireless signals in accordance with the wireless protocol; and

c. wherein the wireless protocol includes frames defined by multiple time slots including,

i. an initial time slot reserved for a start-frame wireless message from the basestation to multiple field units, the start-frame wireless message from the basestation indicates which field unit is assigned to which of the remaining time slots, and

ii. later time slots. reserved for wireless messages from multiple field units to the basestation.

16. A process control and monitoring system for wirelessly communicating with multiple devices, the system comprising;

a. a basestation that wirelessly communicates with multiple field units in accordance with a wireless protocol;

b. multiple field units that receive wireless signals in accordance with the wireless protocol from the basestation and respond to requests from the basestation via wireless signals in accordance with the wireless protocol; and

c. wherein the wireless protocol includes frames defined by multiple time slots including,

i. an initial time slot reserved for a start-frame wireless message from the basestation, the start-frame wireless message indicating to the field units that multiple time slots within the frame are available for logon requests by field units, and

ii. a later time slot for wireless logon request messages from the field units.

17. The system of claim 16, wherein a time slot, after the time slot for wireless logon request messages from the field units, is reserved for a wireless message from the basestation to any field unit which sends a wireless logon request message.

18. A process control and monitoring system for wirelessly communicating with multiple devices, the system comprising:

a. a basestation that communicates with multiple field units via a wireless signal and in accordance with a wireless protocol;

b. multiple field units that receive wireless signals in accordance with the wireless protocol from the basestation and respond to requests from the basestation via wireless signals in accordance with the wireless protocol; and

c. wherein the wireless protocol includes frames defined by multiple time slots including an initial time slot reserved for at least a portion of a start-frame wireless message from the basestation, the start-frame wireless message directing multiple field units to send data in assigned time slots.

19. The system of claim 18, wherein the start-frame wireless message overrides a selection of data normally sent by a field unit.

20. The system of claim 18, wherein the start-frame wireless message directs at least one of the field units to listen to future messages for data.

21. The system of claim 18, wherein the start-frame message acknowledges an earlier message sent by a field unit.

22. A process control and monitoring basestation for wirelessly communicating with multiple devices, the system comprising:

a. a basestation for communicating with and controlling multiple field units via a wireless signal and in accordance with a wireless protocol;

b. wireless communication and control messages from the basestation sent via a wireless protocol that includes frames defined by multiple time slots; and

c. an initial time slot reserved for a wireless start-frame message from the basestation, the wireless start-frame message from the basestation assigning the remaining time slots, and providing information for synchronizing with the wireless communication and control messages.

23. The basestation of claim 22, wherein a header portion of the wireless start frame message from the basestation includes a unique identifier for indicating with which field unit the basestation is attempting to communicate.

24. The basestation of claim 22, wherein the basestation requests data related to a manufacturing process via the wireless communication and control messages.

25. The basestation controls parameters of a manufacturing process via he wireless communication and control messages.

26. Process control and monitoring field units for wirelessly communicating with multiple devices, the system comprising;

a. multiple field units that receive wireless communication and control messages in accordance with wireless protocol and respond to requests via wireless signals in accordance with a wireless protocol;

b. wireless communication and control messages sent via a wireless protocol that includes frames defined by multiple time slots; and

c. an initial time slot reserved for a wireless start-frame message for communicating with the multiple field units, the wireless start-frame message assigning the remaining time slots to different field units, and providing information synchronizing the field units with the wireless communication and control messages.