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WIKA operating instructions, model GDM-100-T
EN
14535893.01 01/2022 EN/DE
5.5.2.3 Data logger
The data logger is used for recording measured values over a certain time span.
After setting up COM ports, the baud rate and the min./max. address or interval, the
recording can be started. For continuous recording, it is possible to record the measured
data in the selected interval in a text file divided by tabs.
The recording is started with the green start symbol. Stop the recording using the red
stop symbol.
5.5.2.4 Modbus
®
register and functional description
The following documents (available under www.Modbus.org) are recommended for
understanding the Modbus
®
architecture which the following chapters will refer to.
■
Modbus APPLICATION PROTOCOL SPECIFICATION
■
Modbus over Serial Line Specification and Implementation Guide
The register structure is described in the following.
Communication via messages
General form of the messages
Instrument address
Function
Data
CRC check
8 bit
8 bit
n x 8 bit
16 bit
In accordance to Modbus
®
specification, separate messages must be divided by an
intermission of at least 3.5 characters.
The characters within one message may not have spacing of more than 1.5 characters.
Examples of a typical transmission:
Intermission Message 1
▶
Intermission Message 2
▶
Intermission Message 3 ...
5. Commissioning, operation
