4301-MBP-DFCM Redundant Module European and American Spare Parts SIS System

Description

4301-MBP-DFCM application
Widely used in electrical installations, automatic control, and scheduling systems in departments such as power, postal and telecommunications, petroleum, coal, metallurgy, railways, and municipal administration

Model Selection
Name: 4301-MBP-DFCM
Input range: DC0~75mA
Output range: DC4~20mA
Auxiliary power supply: DC24V ± 15%

The following topics describe the flow of data between the two pieces of hardware (ControlLogix processor and MVI56-MBP module) and other nodes on the Modbus Plus network under the module’s different operating modes. Note that all four modes can operate effectively simultaneously if desired. Under most likely operating cases, the Global Input and Global Output tasks will be operating in conjunction with either the Master or the Slave driver.

Global Data Out Mode When the MVI56-MBP module’s Global Output capability is enabled, up to 32 words of data can be transferred onto the Modbus Plus network by the module. This data, typically reserved for high-speed data such as for application control data, is transmitted each time the module receives the network token. The number of words transferred to the Modbus Plus network is user determined through the Module Configuration Block. The following flow chart and associated table describe the flow of data into and out of the module.

The Slave Driver

Mode allows the MVI56-MBP module to respond to data read and write commands issued by other nodes on the Modbus Plus network. Two aspects of the module’s operation must be kept in mind when considering using this mode: 1 The module supports MSTR Type 1 and Type 2 commands issued from a Modicon processor or another device acting in a similar capacity. 2 The module is a Modbus Plus Host type of node, therefore any device wishing to read or write data from the module must be able to define a Data Slave Input Path in the Routing Path. The module supports all 8 Data Slave Input paths, but a Data Slave Path of 0 (zero) will cause the command to be rejected.

There are no special module configuration requirements to place the module in the Slave Operating Mode. When the module is operating in the slave mode, external devices act as masters by polling for data from the module or writing to the module. As such, the module needs to only respond to read and write commands, transferring data to/from the module’s database depending on the command type.

In order for a Modicon PLC to read data from the MVI56-MBP module, a MSTR Type 2 instruction must be entered in the Modicon’s ladder program. This instruction initiates a Modbus Plus network transaction between the PLC and the module. In the configuration of the command, the programmer can specifically choose the location and amount of data to be read from the module and returned to the Modicon’s memory.