ModbusTCP Master, Generic

Provides high-speed control and monitoring of a ModbusTCP slave/server device over Ethernet with ModbusTCP industrial standard.

Each function block is dedicated to one remote device. Many function blocks allow simultaneous control and monitoring of many devices.

A sample function block view is shown below. It provides the key details and access to the programmer.

The IP address of the server device must be entered.

The actual polling period indicates how often each parameter's data is updated.

Click the Program parameter to begin or to examine the details.

Programming is simple and intuitive, especially where parameters and function blocks have been especially named for their purpose. In the following screenshots taken from an example bag machine, most parameters and function blocks have been renamed for clarity.

Begin under the 'High Priority' tab by clicking the plus button to add a read or write command. The following screenshot shows the available, supported function codes. Floating point commands ensure that two consecutive parameters, starting at the given address, are processed concurrently.

In the newly created line, click in the first box to the right of the read or write command. Enter or select the source parameter for the read or write.

The next box to the right is the address of the destination for the read or write data.

Function codes that support multiple, sequential reads or writes have another box to the right of the 'X' multiplication symbol. Select the number of sequential parameters to read or write.

Medium priority, low priority, and setup commands are programmed similarly. Setup commands are processed only once upon initiation of communication.

Click the Configuration tab

Comms Time Allocation allows the bandwidth to be prioritized among the three levels; high, medium, and low. The naming of the levels is a suggested guide. The priority could be given to the 'low-priority' group by sliding its divider to the left.

Comms Gap Time defaults to 5ms to reduce network loading. After each read or write command, the controller waits for the given period before the next command is issued.

• Available only in the dw2xx-v2 series products
• Requires library: Process Control (option -05)
• Firmware versions 0x210C and later

ModbusTCP Master - IP Address

Required entry. The IP address of the ModbusTCP Slave Server device that this block is communicating with.

ModbusTCP Master - Port

Typically, this parameter must be left at standard, 502.

ModbusTCP Master - Enable

The function block is only active when this parameter is enabled.

No commands or updates are possible when disabled.

ModbusTCP Master - Program

The elapsed time after sending a command and receiving no response beyond which a comms timeout error is indicated and logged.

ModbusTCP Master - Actual Polling Period - High

All high-priority parameters are updated every period.

ModbusTCP Master - Actual Polling Period - Medium

All medium-priority parameters are updated every period.

ModbusTCP Master - Actual Polling Period - Low

All low-priority parameters are updated every period.

ModbusTCP Master - Program

Click the Program parameter to begin or edit or examine the details of an existing program.