OTT HydroMet SUTRON XLINK 100, Operation & Maintenance Manual

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Float is a IEEE 32 bit floating point value.
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Double is a IEEE 64 bit floating point value.
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Discrete means that the sensor returns one byte and that the result is based on the least
significant bit of the byte.
Modbus MSW
For certain Modbus Value (Int, Uint, Float, Double), Modbus MSW determines which register is used to
contain the most significant word (MSW) of the tag's value. When set to "Low Reg", the lower register of
the register pair is used to contain the MSW.
Modbus Timeout
Modbus Timeout is the amount of time in seconds that the station will wait for a reply from the sensor.
Modbus Retries
Modbus Retries indicates how many times the station will retry to issue the command to a sensor in case
of failures. Please note that some sensors require at least one retry to work at all. For those sensors, the
initial command only wakes the sensor up after which the sensor replies to the retry.
19.4 Modbus Server Function Codes
The following table identifies the functions that are supported. Each diagnostic counter is cleared when
the device is powered up or reset.
Code Hex Subcode Hex
Read Holding Registers 0x03
Read Input Register 0x04
Write Single Register 0x06
Diagnostic 0x08 Return Query Data 0x00
Diagnostic 0x08 Clear Counters 0x0A
Diagnostic 0x08 Return Bus Message Count 0x0B
Diagnostic 0x08 Return Bus Comm Error 0x0C
Diagnostic 0x08 Return Bus Exception Count 0x0D
Diagnostic 0x08 Return Server Message Count 0x0E
Diagnostic 0x08 Return Server Broadcast Count 0x0F
Diagnostic 0x08 Return Bus Char Overrun Count 0x12
Write Multiple Registers 0x10
Sutron Function Code 0x41 Get Log GL
Sutron Function Code 0x41 Get File GF
Sutron Function Code 0x41 Send File SF
19.4.1 Identifying Registers
There are two types of data that can be accessed using the Modbus protocol. These include Holding and
Input registers.