VersaTRAK RTUs with version 2.16 and newer firmware support a flexible suite of communications options in support of your open systems:

Ethernet Port

The Ethernet port on a VersaTRAK RTU will auto detect and respond to both SIXNET "I/O for Windows" and Open Modbus (Modbus/TCP) protocols. Messages from multiple computers can be received simultaneously in a mix of these two protocols. Many TCP/IP sessions and any number of UDP connections can exist at the same time.

RS485 Port

The RS485 port on a VersaTRAK RTU can serve as either a slave (receive I/O commands) or master (send I/O commands). In either of these two modes, the RS485 port can be configured for either SIXNET "I/O for Windows", Modbus RTU, or Modbus ASCII protocol. (Please note that RS485 communications requires a single choice of mode and protocol which is selected using the Plant Floor configuration software supplied with your VersaTRAK RTU.)

Passthru Mode

When a VersaTRAK RTU receives a message over Ethernet or a serial port, addressed to a station other than itself, it can pass this message to one of its serial ports for retransmission to other devices connected to this "passthru" port. The response from the remote device is retransmitted in the proper format over the serial port to the originating master station. Please note that "I/O for Windows" communications will enable you to use many advanced SIXNET features, such as on-the-fly configuration changes, directly through the VersaTRAK RTU.

Selecting "I/O for Windows" or Modbus Protocol

Generally, "I/O for Windows" is the preferred protocol for SIXNET systems. In most cases it results in higher system performance, and gives you the many benefits designed into SIXNET products, such as addressing I/O directly by tag name, and the many advantages provided by the Control Room Shared Resource Database in Windows-based systems. Systems using "I/O for Windows" communications can be configured on-line (while live) and can be addressed by multiple masters simultaneously.

Modbus is a single master protocol (although Ethernet can extend this capability in some situations). Modbus is recommended when the SIXNET I/O will share a communications channel with existing Modbus devices or when the software in your master station can only talk Modbus protocol. This is generally the case with non-Windows legacy systems and Windows software with limited suites of supported I/O drivers.