IDEC FC6A-C16K1CE Communications Manual page 149

6: M C
ODBUS OMMUNICATION
Master Device Address
When function code 01, 02, 03, or 04 is selected to read data from Modbus servers, designate the first data register or internal
relay number to store the data received from the Modbus server. When function code 05, 06, 15, or 16 is selected to write data to
Modbus servers, designate the first data register or internal relay number to store the data to write to the Modbus server. Data
registers and internal relays can be designated as the master device address.
Data Size and Word/Bit
Designate the quantity of data to read or write. The valid data size depends on the function code. When function code 01, 02, 05,
or 15 is selected, designate the data size in bits. When function code 03, 04, 06, or 16 is selected, designate the data size in
words. For valid data sizes, see "Function Code" on page 6-22.
Remote Host No.
Designate the remote host number configured in the Remote Host List dialog box. In the Remote Host List dialog box, IP address
and port number are configured for each remote host. The default port number of Modbus TCP communication is 502. If the
Modbus TCP server uses a different port number, configure that port number in the Remote Host List dialog box.
Slave No.
Designate slave numbers 1 through 247. The same slave number can be designated repeatedly for different request numbers
which can be 1 through 255. The slave number is usually not referred by Modbus TCP server. Configure the slave number if
Modbus TCP server requires.
Slave Address
Designate data memory addresses of Modbus servers. The valid slave address range depends on the function code. For valid slave
addresses, see the table above. The allocations of memory addresses vary with each Modbus server device. Refer to manuals for
each Modbus server device.
Request Execution Device
To use request execution devices, click the radio button for "Use" and designate the first internal relay or data register in the
Modbus TCP Client Request Table. Internal relays or data register bits used for executing requests are automatically listed in the
table. To execute a request, turn on the corresponding request execution device.
When request execution devices are not designated, all requests programmed in the Request Table are executed continuously.
Error Status Data Register
To use error status data registers, click the radio button for "Use" and designate the first data register in the Modbus TCP Client
Request Table. Data registers used for storing error statuses are automatically listed in the table. When Use a single DR for all
communication requests is selected, the first data register is shared by all requests.
FC6A S M S A - -O T C M FC9Y-B1730 6-23
ERIES ICRO MART LL IN NE YPE OMMUNICATION ANUAL