Implicit Messaging

Introduction

The recommended for EtherNet/IP implicit message connections are 1/2 of cycle time. If the resulting RPI is less than 25 ms, the implicit message connections may be adversely affected when the diagnostic features of the 140NOC78•00 module are accessed via explicit messaging or .

In this situation, the following timeout multiplier settings are recommended. Refer to the Configuring Communication Module Connection Settings topic to set the timeout multiplier.

RPI (ms)	Recommended Timeout Multiplier	Connection Timeout
2	64	128
5	32	160
10	16	160
20	8	160
25	4	100

NOTE: If you use RPI values lower than recommended, unnecessary bandwidth is consumed on the network, and the module system performance is impacted.

RPI

(requested packet interval) The time period between cyclic data transmissions requested by the scanner. EtherNet/IP devices publish data at the rate specified by the RPI assigned to them by the scanner, and they receive message requests from the scanner at each RPI.

MAST

A master processor task that is run through its programming software. The MAST task has 2 sections:

IN: Inputs are copied to the IN section before execution of the MAST task.
OUT: Outputs are copied to the OUT section after execution of the MAST task.

DTM

(device type manager) A device driver running on the host PC. It provides a unified structure for accessing device parameters, configuring and operating the devices, and troubleshooting the network. DTMs can range from a simple graphical user interface (GUI) for setting device parameters to a highly sophisticated application capable of performing complex real-time calculations for diagnosis and maintenance purposes. In the context of a DTM, a device can be a communications module or a remote device on the network.

See FDT.