Variable Area; Addresses; Number Of Elements; Set Values - Omron KM50 Communications Manual

Section 4 Modbus Communications Protocol

4. 3 Variable Area

The variable area is the region of memory used to exchange data with the KM50-C/-E through
communications.
Operations such as reading the process value and reading/writing parameters are performed on
the variable area. Operation commands, however, do not use the variable area.

■ Addresses

An address is appended to each variable type.
Express addresses in 2-byte hexadecimal and append them for the specified access size.

■ Number of Elements

The number of elements is expressed in 2-byte hexadecimal. The setting range for the number of
elements depends on the command.
Each element consists of two bytes of data, so multiples of two elements are specified. By
specifying multiples of 2 for the number of elements, data is read and written in units of four bytes.
Example: To read one elements, multiple 1 by 2 to get the number of elements to specify, i.e., 2.

■ Set Values

The values read from the variable area or written to the variable area are expressed in
hexadecimal, ignoring the decimal point. (Negative values are given as two's complements.)
Example: 105.0 decimal = 0000 041A hex
The variables are 8-digit hexadecimal values. Negative values are given as two's complements.
The values are hexadecimal values with no decimal point.
4-6
KM50 形E5CN/AN/EN
Microcomputer
Operation
マイコ ン
command
動作 指令 など

Variable area

変 数エリア
読出 / 書込
Read/write