120
5. PARAMETERS
5.7 (N) Communication operation parameters
NOTE
• To use the MODBUS RTU protocol, set "1" in
Pr.549 Protocol selection
.
• If MODBUS RTU communication is performed from the master to the address 0 (station number 0), the data is broadcasted,
and the converter unit does not send any reply to the master. To obtain replies from the converter unit, set
Pr.331 RS-485
communication station number
≠
"0 (initial value)".
• Some functions are disabled in broadcast communication. (Refer to
.)
Communication specifications
• The communication specifications are shown in the following table.
Outline
• The MODBUS communication protocol was developed by Modicon for programmable controllers.
• The MODBUS protocol uses exclusive message frames to perform serial communication between a master and slaves.
These exclusive message frames are provided with a feature called "functions" that allows data to be read or written. These
functions can be used to read or write parameters from the converter unit, or check the converter unit's operating status,
for example. This product classifies the data of each converter unit into holding register area (register address 40001 to
49999). The master can communicate with converter units (slaves) by accessing pre-assigned holding register addresses.
NOTE
• There are two serial transmission modes, the ASCII (American Standard Code for Information Interchange) mode and the RTU
(Remote Terminal Unit) mode. However, this product supports only the RTU mode, which transfers 1 byte data (8 bits) as it
is. Also, only communication protocol is defined by the MODBUS protocol. Physical layers are not stipulated.
Item
Description
Related parameter
Communication protocol
MODBUS RTU protocol
Pr.549
Conforming standard
EIA-485 (RS-485)
—
Number of connectable units
1: N (maximum 32 units), the setting range of station number is 0 to 247.
Pr.331
Communication speed
Selected among 300/600/1200/2400/4800/9600/19200/38400/57600/76800/
115200 bps
Pr.332
Control procedure
Asynchronous method
—
Communication method
Half-duplex system
—
Communication
specifications
Character
system
Binary (fixed at 8 bits)
—
Start bit
1 bit
—
Stop bit length
Select from the following three types:
No parity check, stop bit length 2 bits
Odd parity check, stop bit length 1 bit
Even parity check, stop bit length 1 bit
Pr.334
Parity check
Error check
CRC code check
—
Terminator
Not available
—
Time delay setting
Not available
—
Содержание FR-CC2-N Series
Страница 61: ...60 3 PRECAUTIONS FOR USE OF THE CONVERTER UNIT 3 4 Checklist before starting operation MEMO ...
Страница 137: ...136 5 PARAMETERS 5 10 Checking parameters changed from their initial values initial value change list MEMO ...
Страница 153: ...152 6 PROTECTIVE FUNCTIONS 6 6 Check first when you have a trouble MEMO ...
Страница 165: ...164 7 PRECAUTIONS FOR MAINTENANCE AND INSPECTION 7 2 Measurement of main circuit voltages currents and powers MEMO ...
Страница 171: ...170 8 SPECIFICATIONS 8 3 Outline dimension drawings MEMO ...