Method of determining request transmission priority subject to request content and transmitting request subject to such request transmission priority in application of Fieldbus communication framework
A method of determining request transmission priority subject to request content and transmitting request subject to such request transmission priority in application of Fieldbus communication framework in which the communication device determines whether the received requests have the priority subject to the respective content, and also determines whether there is any logical operation condition established, and then the communication device transmits the received external requests to the connected slave device as an ordinary request or priority request, preventing the slave device from receiving an important external request sent by the main control end or manager at a late time.
1. A method of determining request transmission priority subject to request content and transmitting request subject to such request transmission priority in application of Fieldbus communication framework, comprising the steps of:
(a) external requests are transmitted from a remote control end to a communication device one after another;
(b) the communication device determines whether a specific content of each received external request corresponds to a priority right, wherein the specific content includes at least one of a request type, a destination slave device address, and a register read/write address;
(c) the communication device determines whether there is at least one logical operation condition established;
(d) the communication device couples the priority right and logical operation conditions of the content of each received external request subject to a user's setting to determine a transmit priority for each received external request;
(e) the communication device transmits each received external request that does not have the priority to transmit as an ordinary request; and
(f) the communication device transmits each received external request that has the priority to transmit as a priority request;
wherein the logical operation condition to be coupled subject to the user's setting is the number of requests having the specific content on a queue.
2. The method as claimed in claim 1 , wherein the priority request transmission procedure is to send the external request into the communication device into a queue having a higher priority.
3. The method as claimed in claim 1 , wherein the priority request transmission procedure is to tag the priority request in the priority position on an original queue.
4. The method as claimed in claim 1 , wherein said communication device categorizes the priority right into different levels or kinds.
5. The method as claimed in claim 1 , wherein the logical operation condition to be coupled subject to the user's setting is the numerical value of a counter/timer.
6. The method as claimed in claim 1 , wherein said communication device is one of the electronic devices including communication gateway, master device, and repeater or device that are capable of receiving different external requests.
7. The method as claimed in claim 1 , wherein when the external requests that are transmitted from said remote control end to said communication device are not in conformity with Fieldbus communication protocol format, the external requests are processed through a format conversion procedure before sending out by said communication device.
8. The method as claimed in claim 1 , wherein the Fieldbus communication framework is one of the framework of CAN, EtherCAT, DeviceNet, Modbus, PROFIBUS, CompuBus and SECS protocols for automated control application that has a master/slave architecture and communication mode of Request, Response or Exception.