摘要:
Example apparatus and methods to communicatively couple field devices to controllers in a process control system are disclosed. An example method of changing a communication protocol of a first field device in a process control system includes decoupling from the first field device a first removable communication module configured to communicate using a first communication protocol. The example method also includes coupling to the first field device a second removable communication module configured to communicate using a second communication protocol. After coupling the second removable communication module, the first field device is configured to communicate using the second communication protocol. In addition, the first field device is coupled to a first communication channel on an input/output card when communicating using the first communication protocol and the first field device is coupled to the first communication channel on the input/output card when communicating using the second communication protocol.
摘要:
A programmable timeswitch comprises a microcontroller and a switching relay for controlling the supply of electricity to electrical apparatus in accordance with a predetermined `yearly` program stored in an EPROM. The yearly program can include different daily programs for weekdays and weekends and includes different seasonal programs to take account of different demands for electricity at different times of the year. The timeswitch is programmed to switch automatically from one seasonal program to the next seasonal program on predetermined dates in the year and so does not have to be re-programmed at intervals throughout the year. The timeswitch may be used as part of a `deferable load program` run by a utility in which a large number of timeswitches are supplied to different installations, the timeswitches having been programmed by a master console under the sole control of the utility.
摘要:
Example apparatus and methods to communicatively couple field devices to controllers in a process control system are disclosed. An example method of changing a communication protocol of a first field device in a process control system includes decoupling from the first field device a first removable communication module configured to communicate using a first communication protocol. The example method also includes coupling to the first field device a second removable communication module configured to communicate using a second communication protocol. After coupling the second removable communication module, the first field device is configured to communicate using the second communication protocol. In addition, the first field device is coupled to a first communication channel on an input/output card when communicating using the first communication protocol and the first field device is coupled to the first communication channel on the input/output card when communicating using the second communication protocol.
摘要:
Apparatus and method are provided for intelligently controlling an electrical power distributor for a personal computer, its peripherals, and other devices. The apparatus includes a parallel interface; single-chip microcomputer; plurality of relays; power source connector; and plurality of electrical outlets. The parallel interface can be removably connected through a parallel cable to a parallel port of a personal computer. The single-chip microcomputer has a clock to keep time independent of the personal computer. In response to programming instructions from the personal computer, the single-chip microcomputer controls the relays to selectively connect and disconnect the power lead connector to the electrical outlets of the distributor. Communicating with the distributor is made user friendly by including a software prorgram for the personal computer that translates simple commands from the user into commands sent through the parallel port of the personal computer to the distributor. The distributor can share the parallel port of the personal computer with another peripheral device, such as a printer, by use of a split-Y parallel cable or similar split cable or connector. The distributor reacts only to particular data transmitted on the split-Y parallel cable and ignores other data. A preferred embodiment of the distributor also includes a phone ring interface for detecting and responding to telephone ring signals. The single-chip microcomputer can be programmed by the personal computer to respond to one or more preselected sequences of one or more phone ring signals.