Control Techniques M'Ax 403, Руководство пользователя

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M’Ax User Guide
91
Issue Number: 4
C.12 MODBUS RTU protocol
Related parameters
The text settings are as follows:
The text settings are as follows:
MODBUS frame
No parity bit is used.
MODBUS commands
MODBUS registers
Mapping of parameters
Drive parameters are mapped to the 4XXXX-series of MODBUS
registers. Menu-parameter numbers are mapped by removal of the
decimal point and the addition of a prefix number (e.g. parameter
number
11.24 is converted to 41124 ). All parameter values (including the
settings of bit parameters and the serial-communications values of text
parameters) are treated as 16-bit values.
Multiple registers
A maximum of 16 consecutively numbered registers can be accessed at
a time.
If one or more parameters in a specified series of parameters does not
exist, the specified action will not be performed and the Drive will
respond with an exception code (see Exception codes below).
Broadcast messages
When address 0.0 is specified by the controller messages will be sent to
all units. These will respond accordingly but will not reply.
Exception codes
Out-of-range conditions
During write-commands
If the value specified in a write-command (0x10) to a Drive exceeds the
maximum permissible value for a parameter, the parameter remains
unchanged. If this occurs during a multiple write-command, subsequent
parameter(s) will also remain unchanged, but the value(s) of the
preceding parameter(s) will have been changed.
The Drive does not send an exception code in reply; only confirmation of
the actual changes is sent to the master.
During a multiple read/write command
If the value specified in a multiple read/write-command (0x17) to a Drive
exceeds the maximum permissible value for a parameter, the parameter
remains unchanged. The values of all preceeding and subsequent
parameters are changed.
No indication of error(s) is sent to the master.
To connect a M’A x Drive to a fieldbus system a gateway device can be
used to convert from one network system to another, such as Devicenet
to Modbus.
Control Techniques Drive Centres can supply a range of gateway
options to suit most common fieldbuses.
11.23
Serial comms. address
ô
0.1 ~ 24.7
ð
1.1
RW Uni P GROUP.UNIT
11.24
Serial comms. protocol selector
ô
0 ~ 1
RW Txt P
11.24 Protocol
0 ANSI
1 MODBUS RTU
11.25
Serial comms. baud rate
ô
0 ~ 6
ð
5
RW Uni P
11.25 Baud rate (bits/s)
0 300
1 600
2 1200
3 2400
4 4800
5 9600
6 19200
11.26
Serial comms. transmit-delay time
ô
0 ~ 255
ð
2
RW Uni P ms
1 start bit 8 data bits 2 stop bits
Function
MODBUS
command code
Read holding registers
Read multiple registers
0x03 (3)
Preset multiple registers
Write multiple registers
0x10 (16)
Read and write multiple registers 0x17 (23)
Code Indicates
1 Invalid command code specified
2
Invalid register address specified (out of range or more than
16 parameters specified)