126
5. PARAMETERS
5.7 (N) Communication operation parameters
• Content of normal response
Example) Read the successful register start address and number of successful accesses from
slave address 25 (H19).
Query message
Normal response (Response message)
The number of holding registers that were successfully accessed was returned as two with the start address 41075 (
Pr.75
).
Error response
• An error response is returned if the query message received from the master contains an illegal function, address or data.
No response is returned for parity, CRC, overrun, framing, and busy errors.
NOTE
• No response is also returned in the case of broadcast communication.
• Error response (Response message)
• Error code list
*1
An error response is not returned in the following cases:
In other words, when function code H03 or H10 is used and multiple holding registers are accessed, an error response is not returned even if a
nonexistent holding register or holding register that cannot be read or written from/to is accessed.
NOTE
• An error response is returned if none of the accessed holding registers exist. When an accessed holding register does not
exist, the read value is 0 and the written data is invalid.
Message
Description
c
Starting address
The start address of the holding register that was successfully accessed is returned.
Starting address = start register address (decimal) - 40001
For example, when starting address 0001 is returned, the holding register address that was
successfully accessed is 40002.
d
No. of points
The number of holding registers that were successfully accessed is returned.
Slave address
Function
CRC check
H19
(8 bits)
H46
(8 bits)
—
(8 bits)
—
(8 bits)
Slave address
Function
Starting address
No. of points
CRC check
H19
(8 bits)
H46
(8 bits)
H04
(8 bits)
H32
(8 bits)
H00
(8 bits)
H02
(8 bits)
—
(8 bits)
—
(8 bits)
a. Slave address
b. Function
c. Exception code
CRC check
(8 bits)
H80 + Function
(8 bits)
(8 bits)
L
(8 bits)
H
(8 bits)
Message
Description
a
Slave address
Set the address received from the master.
b
Function
The function code requested by the master and H80 is set.
c
Exception code
The codes in the following table are set.
Code
Error item
Error description
01
ILLEGAL FUNCTION
The query message from the master has a function code that cannot be handled by the slave.
02
ILLEGAL DATA ADDRESS
The query message from the master has a register address that cannot be handled by the slave.
(No parameter, parameter cannot be read, parameter cannot be written)
03
ILLEGAL DATA VALUE
The query message from the master has data that cannot be handled by the slave.
(Out of parameter write range, a mode is specified, or other error)
(a) Function code H03 (reading data of holding registers)
When the number of registers is specified as one or more and there are one or more holding registers from which data can be read
(b) Function code H10 (writing data to multiple holding registers)
When the number of registers is specified as one or more and there are one or more holding registers to which data can be written.
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 ...
