Panasonic KT7 Instruction Manual page 6

• Response message from the slave in exception (error) status (When non-existent data item
is sent)
Slave
Header
address
(3AH) (30H 31H)
1 2
The function code MSB is set to 1 for the response message in exception (error) status (83H).
The exception code (02H: Non-existent data address) is returned.
2 Setting (Instrument number 1, SV=100 )
• A request message from the master
Slave
Header
address
(3AH)
(30H 31H)
1 2
• Response message from the slave in normal status
Slave
Header
address
(3AH) (30H 31H)
1
• Response message from the slave in exception (error) status (When a value out of the setting
range is set.)
Slave
Header
address
(3AH) (30H 31H)
1
The function code MSB is set to 1 for the response message in exception (error) status (86H).
The exception code (03H: Value out of the setting range) is returned.
6.4 RTU mode
8-bit binary data in command is transmitted as it is.
Data format Start bit
Data bit
Parity
Stop bit
Error detection : CRC-16 (Cyclic Redundancy Check)
Data interval
(1) Message configuration
RTU mode is configured to start after idle time is processed for more than 3.5 character transmission
and end after idle time is processed for more than 3.5 character transmission. (See Fig. 6.4-1)
Slave
3.5 idle
characters address
(2) Slave address
Slave address is an individual instrument number on the slave side and is set within the range
00H to 5FH (0 to 95).
The master identifies slaves by the slave address of the requested message.
The slave informs the master which slave is responding to the master by placing its own address in
the response message.
[Slave address 00H (broadcast address) can identify all the slaves. However slaves do not respond.]
(3) Function code
The function code is the command code for the slave to undertake the following action types (Table
6.4-1).
(Table 6.4-1)
Function code
03 (03H)
06 (06H)
Function Exception
code code
(38H 33H) (30H 32H)
2 2
(Fig. 6.3-4)
Function
Data item
code
(30H 30H 30H 31H) (30H 30H 36H 34H)
(30H 36H)
2 4
(Fig. 6.3-5)
Function
Data item
code
(30H 36H) (30H 30H 30H 31H) (30H 30H 36H 34H)
2 2
(Fig. 6.3-6)
Function Exception
code
(38H 36H)
2 2
(Fig. 6.3-7)
: 1 bit
: 8 bits
: Even/No/Odd (Selectable)
: 1 bit/2 bits (Selectable)
: 3.5 characters transmission time or less
Function
code
(Fig. 6.4-1)
Reading the set value and information from slaves
Setting to slaves
Error check
Delimiter
LRC
(37H 41H) (0DH 0AH)
2
Error check
Data
(39H 34H)
4
Data
4 4
Error check
code LRC
(30H 33H) (37H 36H)
2
2
Error check
Data
CRC
Contents
6
Number of
2
characters
Delimiter
LRC
(0DH 0AH)
Number of
characters
2 2
Error check
Delimiter
LRC
(39H 34H) (0DH 0AH)
2 2
Delimiter
(0DH 0AH)
Number of
characters
2
3.5 idle
characters
Number of
characters