Module libmodbus
lua bindings to libmodbus.
Generally, this provides a very thin layer over libmodbus. Instead of passing the context around to all your modbus_xxx functions, you simply call them as member functions on the context returned by the new() functions.
Info:
- License:
Permission is hereby granted, free of charge, to any person obtaining
a copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Software, and to
permit persons to whom the Software is furnished to do so, subject to
the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- Author: Karl Palsson
Functions
- version ()
-
Returns the runtime linked version of libmodbus as a string.
The compile time version is available as a constant VERSION.
Returns:
-
eg "3.0.6"
See also:
- rkt_new_rtu (device, baud, parity, databits, stopbits)
-
Создать Modbus/RTU контекст - глобальная функция
Parameters:
- device (required) - "internal" - для встроенного в контроллер RS-485
- baud rate, defaults to 19200
- parity defaults to EVEN
- databits defaults to 8
- stopbits defaults to 1
Returns:
-
a modbus context ready for use
- new_rtu (device, baud, parity, databits, stopbits)
-
Не использовать, а использовать глобальную функцию rkt_new_rtu
Parameters:
- device (required)
- baud rate, defaults to 19200
- parity defaults to EVEN
- databits defaults to 8
- stopbits defaults to 1
Returns:
-
a modbus context ready for use
- new_tcp_pi (host, service)
-
Create a Modbus/TCP context
Parameters:
- host eg "192.168.1.100" or "modbus.example.org"
- service eg "502" or "mbap"
Returns:
-
a modbus context ready for use
- set_s32 (num)
-
Write a 32bit (u)int to 2x16bit registers
Parameters:
- num 32bit number
Returns:
- reg1 upper 16bits
- reg2 lower 16bits
- set_f32le (num)
-
Write a bit float to 2x16bit registers
Parameters:
- num floating point number
Returns:
- reg1 upper 16bits of a 32bit float
- reg2 lower 16bits of a 32bit float
- set_f32 (num)
-
Write a bit float to 2x16bit registers
Parameters:
- num floating point number
Returns:
- reg1 upper 16bits of a 32bit float
- reg2 lower 16bits of a 32bit float
- get_s16 (1)
-
16bit register as number to signed 16bit
Parameters:
- 1 16bit register
Returns:
-
signed 16bit number
- get_s32 (1, 2)
-
2x16bit registers as number to signed 32 bit
Parameters:
- 1 16bit register
- 2 16bit register
Returns:
-
32bit number
- get_s32le (1, 2)
-
2x16bit registers as number to signed 32 bit (reverse order)
Parameters:
- 1 16bit register
- 2 16bit register
Returns:
-
32bit number
- get_u32 (1, 2)
-
2x16bit registers as number to unsigned 32 bit
Parameters:
- 1 16bit register
- 2 16bit register
Returns:
-
32bit number
- get_u32le (1, 2)
-
2x16bit registers as number to unsigned 32 bit (reversed order)
Parameters:
- 1 16bit register
- 2 16bit register
Returns:
-
32bit number
- get_f32 (1, 2)
-
2x16bit registers as number to 32 bit float
Parameters:
- 1 16bit register
- 2 16bit register
Returns:
-
32bit float
- get_f32le (1, 2)
-
2x16bit registers as number to 32 bit float (Reversed order)
Parameters:
- 1 16bit register
- 2 16bit register
Returns:
-
32bit float
- get_s64 (1, 2, 3, 4)
-
4x16bit registers as number to signed 64 bit
Parameters:
- 1 16bit register
- 2 16bit register
- 3 16bit register
- 4 16bit register
Returns:
-
64bit number
- get_u64 (1, 2, 3, 4)
-
4x16bit registers as number to unsigned 64 bit
Parameters:
- 1 16bit register
- 2 16bit register
- 3 16bit register
- 4 16bit register
Returns:
-
64bit number
Context Methods
These functions are members of a modbus context, from either new_rtu() or new_tcp_pi()
- ctx:connect ()
- Connect, see modbus_connect()
- ctx:close ()
- Close, see modbus_close()
- ctx:set_debug (enable)
-
Set debug
Parameters:
- enable optional bool, defaults to true
- ctx:set_error_recovery (a, b)
-
Set error recovery, see modbus_set_error_recovery.
The arguments will be or'd together.
Parameters:
- a one of error_recovery_constants
- b one of error_recovery_constants
- ctx:set_byte_timeout (seconds, microseconds)
-
See also modbus_set_byte_timeout
Parameters:
- seconds (required)
- microseconds (optional, defaults to 0)
- ctx:get_byte_timeout ()
-
Returns:
- seconds
- microseconds
- ctx:set_response_timeout (seconds, microseconds)
-
Parameters:
- seconds (required)
- microseconds (optional, defaults to 0)
- ctx:get_response_timeout ()
-
Returns:
- seconds
- microseconds
- ctx:get_socket ()
-
Returns:
-
the socket number
- ctx:set_socket (sock)
-
Parameters:
- sock integer socket number to set
- ctx:rtu_get_serial_mode ()
-
Returns:
-
rtu_constants the serial mode, either RTU_RS232 or RTU_RS485
- ctx:rtu_set_serial_mode (mode)
-
Sets the mode of a serial port.
Remember, this is only required if your kernel is handling rs485 natively.
If you are using a USB adapter, you do NOT need this.
Parameters:
- mode The selected serial mode from rtu_constants, either RTU_RS232 or RTU_RS485.
- ctx:set_slave (unitid)
-
Parameters:
- unitid the unit address / slave id to use
- ctx:read_input_bits (address, count)
-
Parameters:
- address
- count
Returns:
-
an array of results
- ctx:read_bits (address, count)
-
Parameters:
- address
- count
Returns:
-
an array of results
- ctx:read_input_registers (address, count)
-
Parameters:
- address
- count
Returns:
-
an array of results
- ctx:read_registers (address, count)
-
Parameters:
- address
- count
Returns:
-
an array of results
- ctx:report_slave_id ()
-
Returns:
-
a luastring with the raw result (lua strings can contain nulls)
- ctx:write_bit (address, value)
-
Parameters:
- address
- value either a number or a boolean
- ctx:write_register (address, value)
-
Parameters:
- address
- value
- ctx:write_bits (address, value)
-
Parameters:
- address
- value as a lua array table
- ctx:write_registers (address, value)
-
Parameters:
- address
- value as a lua array table, or a sequence of values.
Usage:
either ctx:write_registers(0x2000, {1,2,3}) ctx:write_registers(0x2000, 1, 2, 3)
Constants provided for use
Constants used in various functions, either as arguments or returns
- rtu_constants
-
RTU Mode Constants
Fields:
- RTU_RS232
- RTU_RS485
See also:
- error_recovery_constants
-
Error Recovery Constants
Fields:
- ERROR_RECOVERY_NONE
- ERROR_RECOVERY_LINK
- ERROR_RECOVERY_PROTOCOL
See also:
- exception_codes
-
Exception codes
These are all MODBUS_xxxx upstream in libmodbus.
Fields:
- EXCEPTION_ILLEGAL_FUNCTION
- EXCEPTION_ILLEGAL_DATA_ADDRESS
- EXCEPTION_ILLEGAL_DATA_VALUE
- EXCEPTION_SLAVE_OR_SERVER_FAILURE
- EXCEPTION_ACKNOWLEDGE
- EXCEPTION_SLAVE_OR_SERVER_BUSY
- EXCEPTION_NEGATIVE_ACKNOWLEDGE
- EXCEPTION_MEMORY_PARITY
- EXCEPTION_NOT_DEFINED
- EXCEPTION_GATEWAY_PATH
- other_constants
-
Other constants
Fields: