System for communicating messages via a forward overhead control channel for a programmable logic control device
View Patent ↗Communicating commands and/or data to a remote controller, such as a programmable logic controller, coupled to a cellular communications device. Each cellular communications device can monitor the cellular network control channel for a pair of target pages within a first time period. In the event that a cellular communications device receives target pages having a matching specific identifier, the device will monitor the cellular network control channel over a second time period for at least one command page or data page. The cellular communications device can respond to the reception of one or more command or data pages by forwarding instructions or information to the controller via a communications link. In addition, the cellular communications device can acknowledge receipt of the data or command pages by issuing an acknowledgment signal.
1. A method for communicating a programming command to a programmable logic controller (PLC) by sending multiple pages via a cellular network control channel of a cellular mobile radio telephone system to a cellular communications device, comprising the steps of:
monitoring the cellular network control channel for a pair of target pages, each of the target pages having a specific identifier associated with the cellular communication device;
responsive to receiving the pair of target pages, monitoring the cellular network control channel for a schedule command page comprising a memory location, the memory location comprising a programming command for the PLC;
responsive to receiving the schedule command page, transmitting the memory location from the cellular communications device to the PLC to initiate the programming command stored at the memory location.
2. The method of claim 1 , wherein the step of monitoring for the pair of target pages occurs during a first time period and the step of monitoring for the schedule command page occurs during a second time period.
3. The method of claim 1 , further comprising the step of, responsive to receiving the pair of target pages, activating a timer.
4. The method of claim 1 , wherein if the schedule command page specifies that a pair of command pages carry data, then
monitoring the cellular network control channel for the second of the schedule command pages.
5. A communications device, operable for receiving multiple pages via a cellular network control channel and communicating a programming command to a PLC coupled to the communications device, the communications device operable to:
monitor the cellular network control channel for a pair of target pages, each of the target pages having a specific identifier associated with the communications device;
responsive to receiving the pair of target pages, monitor the cellular network control channel for a schedule command page comprising a memory location, the memory location comprising a programming command for the PLC;
responsive to receiving the schedule command page, transmit the memory location from the communications device to the PLC to initiate the programming command stored at the memory location.
6. The communications device of claim 5 , further operable to monitor for the pair of target pages during a first time period and monitor for the schedule command page during a second time period.
7. The communications device of claim 5 , further operable for activating a timer in response to receiving the pair of target pages.
8. The communications device of claim 5 , further operable for monitoring the cellular network control channel for a second of the schedule command pages if the schedule command page specifies that a pair of command pages carry data.