Emerson MMI-20019043 Manuel D’Utilisation

6.6.3

Configure Modbus/RS-485 communications

Display

OFF-LINE MAINT

 > OFF-LINE CONFG > COMM

ProLink II

ProLink

 > Configuration > Device > Digital Comm Settings

ProLink III

Device Tools

 > Configuration > Communications > RS-485 Terminals

Field Communicator Configure > Manual Setup > Inputs/Outputs > Communications > Set Up RS-485 Port

Modbus/RS-485 communications parameters control Modbus communication with the
transmitter's RS-485 terminals.

Modbus/RS-485 communications parameters include:

•

Disable Modbus ASCII

•

Protocol

•

Modbus Address

 (Slave Address)

•

Parity

, Stop Bits, and Baud Rate

•

Floating-Point Byte Order

•

Additional Communications Response Delay

To configure Floating-Point Byte Order or Additional Communications Response Delay, you must use ProLink II.

1.

Set Disable Modbus ASCII as desired.

Support for Modbus ASCII limits the set of addresses that are available for the
transmitter's Modbus address.

1–127, excluding 111 (111 is reserved to the service port)

1–15, 32–47, 64–79, and 96–110

2.

Set Protocol to match the protocol used by your Modbus/RS-485 host.

8–bit communications

7–bit communications

If support for Modbus ASCII is disabled, you must use Modbus RTU.

3.

Set Modbus Address to a unique value on the network.

Integrate the meter with the control system

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