Eaton EMR-4000 - Page 282

EMR-4000 IM02602009E
Modbus RTU
Part 1: Configuration of the Devices
Call up »Device parameter/Modbus« and set the following communication parameters:
Slave address, to allow clear identification of the device; and
Baud rate.
Also, select the RS485 interface-related parameters such as:
Number of data bits;
One of the following supported communication variants:
Number of data bits,
Even,
Odd,
Parity or no parity, or
Number of stop bits;
»t-timeout« : communication errors are only identified after expiration of a supervision time »t-timeout« ; and
Response time (defining the period within which an inquiry from the master has to be answered).
Part 2: Hardware Connection
For hardware connection to the control system, there is an RS485 interface at the rear side of the device
(RS485, fiber optic or terminals).
Connect the bus and the device (wiring).
Up to 32 devices can be connected to the bus (point to point connection/spurs).
Connect a terminating resistor to the bus.
Error Handling - Hardware Errors
Information on physical communication errors, such as:
Baud rate error and
Parity error;
can be obtained from the event recorder.
Error Handling – Errors on Protocol Level
If, for example, an invalid memory address is inquired, error codes will be returned by the device that need to be
interpreted.
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