The Radio Statistics section displays the number of received and transmitted wireless packets.

Technical Note: Using the MultiHop Ethernet Data Radio with an EtherNet/IP® or Modbus

RTU System

The MultiHop Ethernet Data Radio is designed specifically to send small amounts of data very long distances. This long range

comes at the expense of throughput, requiring you to slow down data throughput significantly compared to other wireless short

range systems. When using the Ethernet data radio to replace an ethernet cable, some timing parameters need to be relaxed on the

EtherNet/IP or Modbus/TCP host system and unnecessary ethernet traffic limited.

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EtherNet/IP systems have a requested packet interval (RPI); the maximum allowable RPI is 3200 milliseconds.

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Modbus/TCP systems have a timeout.

Star Topology Mode

The time to transmit data in star mode is 150 milliseconds per 60 registers (120 bytes) over an EtherNet/IP or Modbus TCP/IP

connection.

The absolute minimum requested packet interval (RPI) for a simple, one hop system is 100 milliseconds for 60 registers (120 bytes)

over an EtherNet/IP or Modbus TCP/IP connection. Do not set the RPI faster than 100 milliseconds.

Example 1 - Using an EtherNet/IP host system and four remote devices

Each remote device has an input and output assembly connection of 60 registers or less, for a total of 4 × 2 = 8 connections. Set the

EtherNet/IP's host system RPI to a minimum of 8 × 150 milliseconds, or 1,200 milliseconds.

Example 2 - Using one remote device to provide 1,000 registers of input data

A connection consisting of 1000 registers of input data will take 17 radio transmissions to send all the registers (1000 ÷ 60 = 17),

requiring 17 × 150 milliseconds = 2,250 milliseconds. Because this device also has an output connection of six registers that

requires an additional 150 milliseconds, set the RPI to 2400 or higher.

Sure Cross® MultiHop Ethernet Data Radio

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