Module: Modbus® (Modbus)
Modbus RTU
Part 1: Configuration of the Devices
Call up
»Device parameter/Modbus«
and set the following communication parameters there:
•
Slave-address, to allow clear identification of the device.
•
Baud-Rate
Also, select below indicated RS485 interface-related parameters from there, such as:
•
Number of data bits
•
One of the following supported communication variants: Number of data bits, even, odd, parity or no
parity, number of stop bits.
•
»t-timeout«
: communication errors are only identified after expiry of a supervision time
»t-timeout«
.
•
Response time (defining the period within which an enquiry 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 bus and device (wiring).
Error Handling - Hardware Errors
Information on physical communication errors, such as:
•
Baudrate Error
•
Parity Error ...
can be obtained from the event recorder.
Error Handling – Errors on protocol level
If, for example, an invalid memory address is enquired, error codes will be returned by the device that need to be
interpreted.
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EN MRU4 10/09
