GE P485 instruction manual Protocol configuration, Blocks

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DATA EXCHANGE

•Status register (0x0000 to 0x0001): If enabled, this register occupies the first two bytes in the input data area. For more information, see Control and status registers on page 8–1.

•Input data area (0x002 to 0x00F3): This area holds data that should be sent to the fieldbus (see the status and control registers).

•Control register (0x0200 to 0x0201): If enabled, these register occupies the first two bytes in the output data area. For more information, see Control and status registers on page 8–1.

•Output data area (0x200 to 0x2F3): This area holds data received from the fieldbus. Data cannot be written to this area.

•General data Area (0x0400 to 0x7FF): This data cannot be accessed from the fieldbus, and should be used for transfers between nodes on the sub-network, or as a general “scratch pad” for data.

Protocol configuration

DESCRIPTION In order to be able to communicate on the Modbus sub-network, the P485 must be supplied with a description of the required sub-net protocol. To accomplish this, the EnerVista P485/D485 Setup software features a flexible protocol-programming system, allowing the P485 to interpret and exchange data with almost any serial device on the Modbus sub-network.

COMMUNICATION MODE The P485 supports the Modbus Master communication mode. In this mode, the P485 is setup to use the Modbus RTU protocol and implements a Modbus master for data exchange between the fieldbus and one or more devices on the sub-network. Refer to Chapter 5 for additional details.

PROTOCOL BUILDING A description of the building blocks used to describe the sub-net protocol is shown below.

BLOCKS

Node

Message frame

 

Transaction

Byte

Word

Data

CRC

Byte Frame objects

Message frame

Transaction

Byte

Word

Data

CRC

Byte

Frame objects

 

Message frame

 

 

 

 

 

 

 

Frame objects

Byte

Word

Data

CRC

Byte

 

 

 

 

 

 

Figure 3-3: Modbus protocol blocks

•Node: In the P485, a node holds all transactions and parameters for a particular device on the sub network.

•Transaction: Transactions contains messages to be transmitted on the sub-network. A transaction consists of one or more message frames (see figure above), and has a few general parameters to specify how and when the transaction should be used on the sub-network.

•Commands: A command is a pre-defined transaction that has been stored in a list in the EnerVista P485/D485 Setup software. This improves readability as well as simplifying common operations by allowing transactions to be stored and reused.

P485 MODBUS TO PROFIBUS CONVERTER – USER GUIDE

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Contents GE Multilin P485 Modbus to Profibus ConverterPage P485 Modbus to Profibus Converter Table of contentsSoftware Frame Miscellaneous Getting started IntroductionInput and output definition Document conventionsFeatures FeaturesAbout the P485 Modbus to Profibus Converter Mechanical Housing SpecificationsOrdering CommunicationsInstallation Quick installElectrical installation Pin Signal Description Profibus connector pin assignmentsPin Description Configuration cable pin assignments P485 endConfiguration cable PC end Indicators and switches Mechanical installationNumber Description State Status P485 status indicatorsInput/output bytes required Modules Profibus installation procedure Poor performance TroubleshootingOverview Data exchangeMemory Map Address Contents AccessBlocks Protocol configurationData Exchange Installation procedure Software overviewIntroduction Select Configuration Wizard and click on OK Using the EnerVista P485/D485 Setup softwareTypical network arrangement Sub-network data flow Address Command Software Overview P485 Modbus to Profibus Converter User Guide Software Overview Configurator main window Configuration main windowInformation window Function Description Fieldbus configurationP485/D485 configuration P485/D485 configurationParameter Description Range Modbus network configurationSoftware Overview PLC Communication modelP485 scan list Basic settingsMenu NodesCommunication Model P485 Modbus to Profibus Converter User Guide Communication Model Frame editor Frame and command editorsSelect command window Command editorQuery Column Select ‘Add Command’ as described earlierMain window Modbus network monitor Modbus network and node monitorsStart / Stop sub network scanning Node monitor Update OFF Update onCommand Area Control and status registers Advanced functionsCode Name Description Bits Name DescriptionHandshake bits themselves bits 14 Code Error DescriptionFieldbus control system Input/output data during startupMailbox command Advanced fieldbus configurationAdvanced Functions Overview Application exampleType Parameter Address Format Read/write For the MM2, we haveParameter User map data Address Modbus user map setupMM2 meter user map setting System configuration System configurationDB9 pin Description Setup Software Starting Configuration WizardModbus network properties Selecting the SUB-NETWORK PropertiesParameters configured for Pqmii 11 Connect devices to sub-network Connect Devices to the SUB- Network14 Select parameter window Select Parameters for Each Node17 Configuration report Queries 20 Save device file21 Expanding the tree 23 Changing configuration parameters for a query 25 Opening a saved configuration file Profibus network setup Miscellaneous WarrantyRevision history Release Dates10-2 6-3 P485 Modbus to Profibus Converter IndexPower Supply
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