Echelon SmartServer 2.2 - Manual (Page 281)

282 Using the SmartServer as Network Management Tool
Single bit, read-write data that has two states (on/off)

Discrete Input (Function 2). Single bit, read-only data that has two
states (on/off).

Input Register (Function 4). 16-bit read-only data that can be
interpreted as a numeric value, a bit map, or an ASCII character.

Hold Register (Functions 3 & 6 single-write). For a single register.
16-bit write data that can be interpreted as a numeric value, a bit map,
or an ASCII character.

Hold Register (Functions 3 & 16 multi-write). For multiple
registers. 16-bit write data that can be interpreted as a numeric value,
a bit map, or an ASCII character. This is the default.
Data Point Value
is Indicates whether the value of the data point is read-only, or read-write.
This is determined by the selected Modbus Data Access Type.
Data Addressing
Parameters
Length Enter the length of the data point. Enter a value and select whether it is
measured in bits or bytes. The default is 2 bytes.
Start Address
(Decimal)
Enter the start address of the register to be used to read or write to the data
point. If the Length property is configured to use bits, you can select the
start and stop bits in the address.
The Modbus driver is configured to ensure that the start and stop
addresses remain consistent with the Length property. This means that if
Length property is changed, he Start Address and Stop Address
properties are automatically updated to fit the desired length. Similarly, if
the Start Address or Stop Address properties are changed, the Length
property is updated accordingly.
Stop Address
(Decimal) Enter the stop address of the register to be used to read or write to the data
point.
Data Type/
Formatting
Parameters
Format
Description Displays the data type (SNVT, UNVT, or built-in type) of the data point.
You can change the data type to any of the SNVT, UNVT, or built-in data
types defined in the resource files on your computer.