Rockwell Automation 900 Temperature Controller Communications Functions - Series B - Manual (Page 83)

5-1 Publication 900-UM004D-EN-E - July 2010
Chapter
5
Communications Data for Modbus
This section lists the details of the communications data in the Modbus
communications protocol.
Variable Area (Setting
Range) List • Four-byte Mode
One element uses 2 bytes of data (H'0000 to H'FFFF), so specify two
element units. Reading and writing in 4-byte units is executed by
specifying an even address and specifying the number of elements in
multiples of 2.
• Two-byte Mode
One element uses 2 bytes of data (H'0000 to H'FFFF), so specify one
element units. Reading and writing in 2-byte data units is executed by
specifying 1-element units.
The following table lists the variable area. Items expressed in hexadecimal in
the “Setting (monitor) value” column are the setting range in the Modbus
specifications. Values in parentheses “()” are the actual setting range.
When there is a section reference for a setting item, refer to that reference for
details.