125
ICC
8.8.11
Modbus RTU Master
To configure the gateway for Modbus RTU Master, click on the
RS-485
Configuration
tab and select
Modbus RTU Master
in the protocol dropdown
menu. The Modbus RTU Master protocol uses service objects to make requests.
For more information on service objects, refer to section 8.5. Each register (input
or holding) in a service object is mapped to 2 bytes in the database (the data type
is fixed at 16-bit). Each discrete (input or coil) is mapped starting at the least-
significant bit of the byte specified by the database address and at each
consecutive bit thereafter. For more information on register and discrete
mapping, refer to section 11.12.2.1.3.
8.8.11.1
Protocol Selection Group
Protocol
Select
Modbus RTU Master
from this dropdown menu.
Baud Rate
Select the desired network baud rate from this dropdown menu.
Parity
Select the desired network parity and number of stop bits from this dropdown
menu.
Timeout
This is the time in milliseconds that the device will wait for a response from a
remote slave after sending a request.
Scan Rate
This is the time the device will wait between sending requests. This may be
useful if slave devices require additional time between requests. If no additional
delay time is needed, set this field to 0. For more information, refer to section
8.4.
8.8.11.2
Modbus Service Object Configuration
This section describes the configurable fields for a Modbus service object. For
more information on Modbus service object editing options, refer to section 8.6.
Type
This group designates the Modbus data type that this service object will access.
Choose from Holding Register, Input Register, Coil Status, or Input Status.
Description
This field is a description of the service object. It is not used on the gateway, but
serves as a reference for the user. Enter a string of up to 16 characters in length.
