User's Manual

Elpro Technologies 450U-E Wireless Ethernet Modem & Device Server User Manual

32 www.cooperbussmann.com/wirelessresources Rev Version 1.4.0

Serial 3.8

The Serial page allows configuration of the onboard serial ports. The 450U-E has two ports, one RS-232, and one RS-

485 port which are used for serial communications with other devices. These ports are completely independent of the

other and can be configured for different functions even utilised at the same time.

The 450U-E offers five different and each port is configured separately by selecting from the drop down list

the appropriate parameters associated with this function.

The Available Port Types are:

Modbus RTU Master This type should be selected when the port is operating as a Modbus Master, i.e. 

Modbus RTU slave devices are connected directly to the serial port. Modbus mappings will need to be

configured in the table provided, see below for details on how this is done.

Expansion I/O This type should be selected when Elpro Serial Expansion modules (115S-XX) are connected to



the modem.

Modbus RTU Slave This type should be used if the port is being used as a Modbus RTU slave, i.e. being 

connected to from a Modbus Master (DCS, Scada, etc.) via the serial port.

Serial Gateway This type should be selected if you wish to allow point to point or point to multipoint 

transparent serial data transfers.

Modbus TCP/RTU Converter This Port Type allows Modbus TCP to Modbus RTU conversion. 

Modbus RTU Master

Port Type

Select Modbus RTU Master from the drop down list.

Data Rate

Serial Data Rate will need to be configured to match that of the serial device that is connected

and communicating via the port. Baud rates available from 110 to 230400 baud.

Data Format

Serial Data Format defines the number of data bits, parity and start/stop bits that is used to

communicate with the serial device.

Flow Control

Flow Control is used by some serial devices to regulate the flow of data by turning on/off flags

that are used to tell the connected serial devices to start or stop transmitting data. The RS232

supports CTC/RTS hardware flow control.

Modbus Scan

Rate

Configures the frequency with which the Slave Device will be polled. Default is 100msec.

Modbus Response

Timeout

This is the time the RTU Master / TCP Client waits for a response from the slave from the

previous poll.

Mapping Master

Mapping Table

Local Register Enter the starting onboard I/O register number that the specified



Modbus Master transaction will transfer I/O to/from depending on whether it is a read or

a write mapping.

I/O count Specify the number of consecutive I/O register that will be transferred in the