Method of determining request transmission priority subject to request channel 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 channel and transmitting request subject to such request transmission priority in application of Fieldbus communication framework in which the communication device determines whether the request channel from which the received requests came have the priority right and 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 channel and transmitting request subject to such request transmission priority in application of Fieldbus communication framework, comprising the steps of:
(a) transmitting a plurality of external requests from a remote control end to a communication device one after another, and the communication device receiving the external requests;
(b) the communication device determining whether the request channel from which the received requests came has a priority right;
(c) the communication device determining whether there is at least one logical operation condition established, wherein the logical operation condition includes an on/off switch function settable by a user;
(d) the communication device coupling the logical operation conditions and the priority right of the request channel on which the received external requests came;
(e) the communication device determining whether the received external requests have a priority to transmit;
(f) the communication device transmitting to a slave device the received external requests that do not have the priority to transmit as ordinary requests; and
(g) the communication device transmitting to a slave device the external requests that have the priority to transmit as a priority request.
2. The method as claimed in claim 1 , wherein the priority request transmission procedure is to tag the priority request in a priority position on an original queue.
3. The method as claimed in claim 1 , wherein said communication device categorizes the priority right into different levels or kinds.
4. 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.
5. The method as claimed in claim 1 , wherein the logical operation condition to be coupled subject to the user's setting is the number of requests on the queue.
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 framework 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 request channel of each external request is one of a TCP port and an UDP port.
9. 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.