Abstract: A heating device includes a heater, a holder, a device frame, a primary positioner, a secondary positioner, and a tertiary positioner. The heater includes a heat generator. The holder holds the heater. The device frame is configured to support the holder. The primary positioner is configured to position the heater and the holder in a longitudinal direction of the heater. The secondary positioner is configured to position the holder and the device frame in the longitudinal direction of the heater. The tertiary positioner is configured to position the device frame and a body of an image forming apparatus in the longitudinal direction of the heater. The primary positioner and one of the secondary positioner and the tertiary positioner are disposed on an identical side defined by a center of the heat generator in the longitudinal direction of the heater.

Abstract: In a control apparatus which transmits/receives data from a central processing unit via a serial transfer channel to a communication control unit, and groups/distributes data of input/output units from the communication control unit via a parallel transfer channel, the control apparatus initiates a diagnosing unit of the parallel transfer channel in response to an instruction issued from the central processing unit, and diagnosis the input/output units subsequent to the diagnosis of the transmission channel. Data input/output timing of the input/output unit is also instructed from the central processing unit, so that the central processing unit can suppress lowering of response speeds caused by the diagnoses, and can maintain the periodicity of the data input/output.

Abstract: In the disclosed control system, loops of 1st path and 2nd path are formed connecting an active CPU unit and each of RIO units, the direction of data frame transfer through the loop of 1st path being opposite to that of the data frame transfer through the loop 2nd path. Reflective electro-optical transducer modules are used in the RIO units which are connected with the active CPU unit so that a standby CPU unit can also be connected. Further, the loop of 1st path and the loop of 2nd path are formed connecting the standby CPU module and each of the RIO modules. The data frame transfer directions through the loops connecting the active CPU unit and each of the RIO units are opposite to the data frame transfer directions through the corresponding loops connecting the standby CPU unit and each of the RIO units.

Abstract: A programmable electronic controller in which one central arithmetic processing unit and a plurality of input devices and output devices are connected by means of a parallel bus, the controller being basically configured to activate a self-diagnostic function and a diagnostic test of the input devices and the output devices with an instruction from a microprocessor of the central arithmetic processing unit; and to judge the result with the microprocessor of the central arithmetic processing unit, by using the microprocessor installed in the central arithmetic processing unit also as a processor for tests (diagnostic tests) of the self-diagnostic function of the input devices and output devices and conducting tests of the self-diagnostic function of the plurality of input devices and output devices with the central arithmetic processing unit.

Abstract: A control device diagnoses the operation of a bus arbiter that mediates bus usage requests output by multiple devices in the control device to satisfy both responsiveness and safety. A diagnostic module, implemented as an external diagnostic module, monitors signals related to the arbiter mediation and, if an abnormality caused by a signal sticking condition or an abnormality in a mediation control unit is detected, stops data transfer safely to prevent safety data from being output incorrectly.

Abstract: In a control apparatus which transmits/receives data from a central processing unit via a serial transfer channel to a communication control unit, and groups/distributes data of input/output units from the communication control unit via a parallel transfer channel, the control apparatus initiates a diagnosing unit of the parallel transfer channel in response to an instruction issued from the central processing unit, and diagnosis the input/output units subsequent to the diagnosis of the transmission channel. Data input/output timing of the input/output unit is also instructed from the central processing unit, so that the central processing unit can suppress lowering of response speeds caused by the diagnoses, and can maintain the periodicity of the data input/output.

Abstract: A programmable electronic controller in which one central arithmetic processing unit and a plurality of input devices and output devices are connected by means of a parallel bus, the controller being basically configured to activate a self-diagnostic function and a diagnostic test of the input devices and the output devices with an instruction from a microprocessor of the central arithmetic processing unit; and to judge the result with the microprocessor of the central arithmetic processing unit, by using the microprocessor installed in the central arithmetic processing unit also as a processor for tests (diagnostic tests) of the self-diagnostic function of the input devices and output devices and conducting tests of the self-diagnostic function of the plurality of input devices and output devices with the central arithmetic processing unit.