Honeywell R0512 manual Access, Bus Initialization, Bus Communication, Runtime Synchronization

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COMMUNICATION

EXCEL 50/100/500/600/800

trollers and devices to exchange data such as measured values, alarms log, and trends. This means that values from one controller or device can be sent to the entire system.

Besides allowing communication between controllers and devices, the C-bus also enables the entire system to be connected to PC front-ends.

When a controller does not have a modem directly connected, the C-bus also allows controllers to communicate with other controllers that do have a modem connected, so that data can be transmitted via the public telephone network.

Access

The C-bus supports multi-master communication using the token passing pro- cedure. A bus master is a controller governing communication between bus devices. The master asks for data and then distributes the data on the bus. Con- trollers transmit data only when asked for it by the master or when they assume the function of the master.

Multi-master communication means that all controllers in the system can function as the master, so the right to request and transmit data is not permanently assigned to a specific controller. This has the advantage that a part of the system can still continue working even if one of the controllers is defective.

The flow of data between devices can be structured hierarchically as part of the software in the user program. Structuring data exchange means defining what infor- mation can be exchanged between which bus devices. Communication is still carried out on the multi-master principle, but bus access time is reduced by con- centrating specific data in specific controllers.

Bus Initialization

When your system first starts up, the software runs a check to see what devices are connected to the C-bus. This process is called initialization. The software stores the information as the Device Type List in the controllers.

During initialization, the bus master requests information about global datapoints from each controller. At the same time, the controllers store the address of the device making the request so that the controllers can subsequently transmit the appropriate data to the appropriate device.

After initialization, each controller knows the address of the next controller with the right to transmit data. If a controller now stops communication, the bus master recognizes that this controller is no longer online and interrupts token passing. As a result, the C-bus reinitializes automatically and also updates the Device Type List, excluding controllers that are no longer online. This ensures continuous bus communication even when individual controllers go off line.

Bus Communication

The Excel 50/100/500/600/800 controller does not transmit any plant-specific data before the C-bus has been initialized. Controller communication depends on the user program stored in each controller. Bus-wide communication occurs when global datapoints have been defined in the user program.

See "Global Datapoints" on page 11 for details on defining global datapoints. During normal operation, the bus master transmits active values. The bus master transmits only values which have changed or which have been requested by another device on initialization or when a device has been offline.

This method of exchanging data reduces the load on the bus and means controllers store only the data they need for their own communication.

I/O Runtime Synchronization

XF525 After application download and after a power failure a runtime synchronization takes place which takes the complete runtime as defined in the datapoint description plus an additional 10%.

EN2B-0092GE51 R0512

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Contents Excel 50/100/500/600/800 Excel 50/100/500/600/800 Contents Subtype Value Hysteresis Trend CycleValue Write Protection Excel 50/100/500/600/800 Section Sensor Offset added Revision OverviewChange System Overview Overview Programming Datapoints Physical DatapointsFlexible Datapoints Pseudo DatapointsGlobal Datapoints Data PointsMapped Datapoints V2.04.xx or higher Attributes Access LevelAcknowledge Alarm V2.04.xx or higher Status text Active State prior toActive State Excel Alarm Status prior to Alarm DelayAlarm Suppression Alarm Status V2.04.xx or higher Alarm TypeAlarm Definition Interval Counter Alarm StatusAttributes Cycle Count Delay Time Switching UpDelay Time Switching Down Feedback Delay High/Low Alarm/Warning LimitsDescriptors Engineering UnitHours Run Log Hours Since ServicedHours Run Alarm Hysteresis HysteresisExample of alarm hysteresis Trend HysteresisIntrinsic Hysteresis for Analog Input Signals Broadcast HysteresisInput/Output Status Text V2.04.xx or higher Interval CountCharacteristic Interval LimitConfigured Activated Or low By DIP Diagram High By @ Pull-Up Resistor HandlingLast Change By plug-in For DI on AI ImpedanceManual Value LED Mode XF823x, XFL823x, and XFx830x modulesMaintenance Alarm Network Variable V2.04.xx or higher Normally Open/Normally Closed V2.04.xx or higherMotor Run Time Off PhaseOperating Mode Resulting value Manual valueRemote value Point Alarms Output TypeSubtype Remote value Resulting ValueScaling Factor Safety Position XFx822x, XFx824x, and XFx830x modulesPulse Duration Suppress Point Switching DownSensor Offset Switch-On Counter Switching down Switching down behaviorTechnical Address Trend LoggingValue Hysteresis Trend CycleValue Room Temp.1.10Number of technical addresses for flexible datapoints Flexible datapoint Number of technical addressesWrite Protection List of Datapoint Attributes Attributes Attributes Time Programs StructureIndividual Time Programs Daily ProgramWeekly Program Annual ProgramToday Function Generating a Time ProgramSpecial Day List Time Programs 04.x Alarm HandlingPrior to System Alarms System alarmsAlarm Alarm text Cond Cause/reason English Code # BenefitsAlarm Handling Warm Start With corresponding function of XBS or XL-Online System Alarms Suppression V .04.xx or higher Data Storage User Program AlarmsAlarms Sent across the System Bus Alarm Handling Test Mode Distributed I/O testing V2.04.xx or higherCommunication System BusAccess Bus InitializationBus Communication Runtime SynchronizationNetwork-Wide Controller Time Synchronization Initialization of Distributed I/O ModulesNew Bus Devices PC Communication Excel IRCRemote Communication Point RefreshingRemote Modem Connection Remote Trending dial-up GeneralController Firmware 2.03.xx and Higher Controller Firmware 2.04.xx and HigherExcel For all other controllers equipped with Flash EpromsMiscelleanous Customize Windows Default Regional and Language SettingsHBS Country and Language Settings XL40A2MMI Care Country Controllers with Internal Text MMI XL Online CentraLine Country and Language Settings CLTG00MMIGraphic MMI CLMMI00N2x Tiger Controllers with Hex Dec Char Unicode ISO/IEC 10646-12000 Character Name Latin Small Letter L Latin Small Letter O with Diaeresis Character Settings Eastern Europe Latin Small Letter D Latin Small Letter U with Ring Above Latin Capital Letter L with Acute Character Settings Turkey Miscelleanous Latin Small Letter D Latin Capital Letter I with DOT Above Latin Capital Letter G with Breve Procedure 1. In Windows, click StartSettingsControl panel Miscelleanous Miscelleanous Miscelleanous Miscelleanous Modemfaq IndexAutomation and Control Solutions