Serial Communication details for diagnostics

Modbus RTU: Modbus is a half-duplex, master-slave communications protocol that allows a single master to communicate with up to 247 slave devices. The Modbus network master reads and writes bits and registers. Modbus RTU is supported by configuring the serial port as Modbus RTU. For more information about the Modbus protocol, see the Modbus Protocol Specifications.

CIP serial: CIP serial uses DF1 full-duplex, half-duplex master, half-duplex slave, and radio modem protocols, providing point-to-point connection between two devices. It combines data transparency (American National Standards Institute ANSI - X3.28-1976 specification subcategory D1) and two-way simultaneous transmission with embedded responses (subcategory F1). L50E and L70E controllers support CIP serial through an RS-232 connection to external devices, such as computers running

RSLinx Classic

software, or other controllers that support CIP serial over DF1 full-duplex, half-duplex master, half-duplex slave, and radio modem, such as

ControlLogix

and

CompactLogix

controllers that have embedded serial ports. The serial port driver can be configured as

CIP serial

,

Modbus RTU

,

DNP3 slave

,

ASCII

, or

Shutdown

through device configuration.

Common Industrial Protocol (CIP): The CIP protocol is a transport and application layer protocol used for messaging over EtherNet/IP, ControlNet, and DeviceNet networks that allows human-machine interfaces to easily connect to an L50E or L70E controller.

DNP3 slave: DNP3 stands for Distributed Network Protocol version 3. It is a standard master-slave protocol used to transfer data to a third-party server. DNP3 protocol can be used in point-to-point and point-to-multipoint communications and multiple slave stations (in DNP3 terminology they are called slave and are PLC, RTU, or other IEDs-Intelligent Electronic Devices).