Brand:NI
Type:SCXI-1349
Origin: the United States
Warranty: 365 days
Colour: new/used
Shipping method: Courier delivery
Spare parts spare parts, the main DCS control system of PLC system and the robot system spare parts,
Brand advantage: Allen Bradley, BentlyNevada, ABB, Emerson Ovation, Honeywell DCS, Rockwell ICS Triplex, FOXBORO, Schneider PLC, GE Fanuc, Motorola, HIMA, TRICONEX, Prosoft etc. Various kinds of imported industrial parts
Data Flow Between the Module and Processor The following topics describe the flow of data between the two pieces of hardware (CompactLogix or MicroLogix 1500-LRP processor and MVI69E-MBS module) and other nodes on the Modbus network. You can configure each port on the module to emulate a Modbus Master device or a Modbus Slave device. 5.4.1 Slave Mode In Slave Driver mode, the MVI69E-MBS module responds to read and write commands issued by a master on the Modbus network. The following diagram shows the data flow for normal Slave mode. Step Description 1 Any time the module restarts (boots or reboots), the Modbus slave port driver receives configuration information from the MBS controller tags. This information configures the serial ports and defines slave node characteristics. The configuration information may also contain instructions to offset data stored in the database to addresses different from addresses requested in the received messages. 2 A Modbus Master device, such as a Modicon PLC or an HMI application, issues a read or write command to the module’s node address.
The port driver qualifies the message before accepting it into the module. Rejected commands cause an Exception Response. 3 After the module accepts the command, the data is immediately transferred to or from the module’s internal database. On a read command, the data is read from of the database and a response message is built. On a write command, the data is written directly into the database and a response message is built. 4 After Steps 2 and 3 have been completed, either a normal response message or an Exception Response message is sent to the Master. 5 Counters are available in the Status Block to permit the ladder logic program to determine the level of activity of the Slave driver. In Slave Pass-Through mode, write commands from the Master are handled differently than they are in Normal mode. In Slave Pass-Through mode, all write requests are passed directly to the processor and data is not written directly into the module’s database.