PHARPS32200000 F8-G2B9B3B6 Power supply module

Data Flow between MVI46-MNET Module and SLC Processor The following topics describe the flow of data between the two pieces of hardware (SLC processor and MVI46-MNET module) and other nodes on the Modbus TCP/IP network under the module’s different operating modes. The module contains both servers and a client. The servers accept TCP/IP connections on service ports 502 (MBAP) and 2000 (MNET). The client can generate either MBAP or MNET requests dependent on the service port selected in the command. The following topics discuss the operation of the server and client drivers.

Description

 1 The server driver receives the configuration information from the configuration file on the Compact Flash Disk, and the module initializes the servers. 

2 A Host device, such as a Modicon PLC or an HMI application issues a read or write command to the module’s node address. The server driver qualifies the message before accepting it into the module. 

3 After the module accepts the command, the data is immediately transferred to or from the internal database in the module. If the command is a read command, the data is read out of the database and a response message is built. If the command is a write command, the data is written directly into the database and the M1 file and a response message is built. 

4 After the data processing has been completed in Step 3, the response is issued to the originating master node. 5 Counters are available in the Status Block that permit the ladder logic program to determine the level of activity of the Server Driver. This data can be placed in the M1 file for use in the ladder logic program. The Module Setup section provides a complete list of parameters that must be defined for a server port.

Client Driver 

In the client driver, the MVI46-MNET module is responsible for issuing read or write commands to servers on the Modbus TCP/IP network. These commands are user configured in the module via the Client Command List received from the module's configuration file (MNET.CFG) or issued directly from the SLC processor (event command control). Command status is returned to the processor for each individual command in the command list status block. The location of this status block in the module's internal database is user defined. The following flow chart and associated table describe the flow of data into and out of the module.