Modbus (j2mod 3.3.0 API)

```
public interface Modbus
```
Interface defining all constants related to the Modbus protocol.

Version:

1.2rc1 (09/11/2004)

Author:

Dieter Wimberger

Field Summary

Fields
Modifier and Type	Field and Description
`static int`	`COIL_OFF` Defines the byte representation of the coil state pos.
`static byte[]`	`COIL_OFF_BYTES` Defines the word representation of the coil state pos.
`static int`	`COIL_ON` Defines the byte representation of the coil state on.
`static byte[]`	`COIL_ON_BYTES` Defines the word representation of the coil state on.
`static int`	`DEFAULT_PORT` Defines the default port number of Modbus (=`502`).
`static int`	`DEFAULT_PROTOCOL_ID` Defines the default protocol identifier (=`0`).
`static boolean`	`DEFAULT_RECONNECTING` Defines the default reconnecting setting for transactions (=`false`).
`static int`	`DEFAULT_RETRIES` Defines the default amount of retires for opening a connection (=`3`).
`static String`	`DEFAULT_SERIAL_ENCODING` Defines the default serial encoding (ASCII).
`static int`	`DEFAULT_TIMEOUT` Defines the default setting for I/O operation timeouts in milliseconds (=`3000`).
`static int`	`DEFAULT_TRANSACTION_ID` Defines the default transaction identifier (=`0`).
`static int`	`DEFAULT_TRANSMIT_DELAY` Defines the default number of msec to delay before transmission Inter-message delays are managed by the SerialTransaction object automatically based on the baud rate.
`static int`	`DEFAULT_UNIT_ID` Defines the default unit identifier (=`0`).
`static boolean`	`DEFAULT_VALIDITYCHECK` Defines the default setting for validity checking in transactions (=`true`).
`static int`	`EXCEPTION_OFFSET` Defines the Modbus slave exception offset that is added to the function code, to flag an exception.
`static int`	`GATEWAY_TARGET_NO_RESPONSE` Defines the Modbus slave exception type `Gateway target failed to respond`.
`static int`	`ILLEGAL_ADDRESS_EXCEPTION` Defines the Modbus slave exception type `illegal data address`.
`static int`	`ILLEGAL_FUNCTION_EXCEPTION` Defines the Modbus slave exception type `illegal function`.
`static int`	`ILLEGAL_VALUE_EXCEPTION` Defines the Modbus slave exception type `illegal data value`.
`static double`	`INTER_CHARACTER_GAP` The number of characters delay that is the allowed maximum between characters on the same serial port (within the same transaction)
`static double`	`INTER_MESSAGE_GAP` The number of characters delay that must be maintained between adjacent requests on the same serial port (within the same transaction)
`static int`	`MASK_WRITE_REGISTER` `mask write register` Update a single register using its current value and an AND and OR mask.
`static int`	`MAX_BITS` Defines the maximum number of bits in multiple read/write of input discretes or coils (2000).
`static int`	`MAX_MESSAGE_LENGTH` Defines the maximum message length in bytes (=`256`).
`static int`	`MAX_TRANSACTION_ID` Defines the maximum value of the transaction identifier.
`static int`	`MINIMUM_TRANSMIT_DELAY` Defines the default number of msec to delay before transmission if not overridden by DEFAULT_TRANSMIT_DELAY (=`2`).
`static int`	`NEGATIVE_ACKNOWLEDGEMENT` Defines the Modbus slave exception type `negative acknowledgment`.
`static int`	`READ_COILS` Defines the class 1 function code for `read coils`.
`static int`	`READ_COMM_EVENT_COUNTER` `get comm event counter` Serial devices only.
`static int`	`READ_COMM_EVENT_LOG` `get comm event log` Serial devices only.
`static int`	`READ_EXCEPTION_STATUS` `read exception status` Serial devices only.
`static int`	`READ_FIFO_QUEUE` `read FIFO queue` Read from a FIFO queue.
`static int`	`READ_FILE_RECORD` `read file record`
`static int`	`READ_HOLDING_REGISTERS` Defines a class 1 function code for `read holding registers`
`static int`	`READ_INPUT_DISCRETES` Defines a class 1 function code for `read input discretes`.
`static int`	`READ_INPUT_REGISTERS` Defines a class 1 function code for `read input registers`.
`static int`	`READ_MEI` Defines the function code for reading encapsulated data, such as vendor information.
`static int`	`READ_MEI_VENDOR_INFO`
`static int`	`READ_MULTIPLE_REGISTERS` Defines the class 0 function code for `read multiple registers`.
`static int`	`READ_SERIAL_DIAGNOSTICS` `get serial diagnostics` Serial devices only.
`static int`	`READ_WRITE_MULTIPLE` `read / write multiple registers` Write some number of registers, then read some number of potentially other registers back.
`static int`	`REPORT_SLAVE_ID` Defines a standard function code for `read slave ID`.
`static int`	`RETRY_SLEEP_TIME` Defines the sleep period between transaction retries in milliseconds (=`200`).
`static String`	`SERIAL_ENCODING_ASCII` Defines the serial encoding "ASCII".
`static String`	`SERIAL_ENCODING_RTU` Defines the serial encoding "RTU".
`static int`	`SLAVE_BUSY_EXCEPTION` Defines the Modbus slave exception type `slave busy`.
`static int`	`SLAVE_DEVICE_FAILURE` Defines the Modbus slave exception type `slave device failure`.
`static int`	`WRITE_COIL` Defines a class 1 function code for `write coil`.
`static int`	`WRITE_FILE_RECORD` `write file record`
`static int`	`WRITE_MULTIPLE_COILS` Defines a standard function code for `write multiple coils`.
`static int`	`WRITE_MULTIPLE_REGISTERS` Defines the class 0 function code for `write multiple registers`.
`static int`	`WRITE_SINGLE_REGISTER` Defines a class 1 function code for `write single register`.

- Field Detail
  - READ_COILS
```
static final int READ_COILS
```
    Defines the class 1 function code for read coils.
    
    See Also:
    
    Constant Field Values
  - READ_INPUT_DISCRETES
```
static final int READ_INPUT_DISCRETES
```
    Defines a class 1 function code for read input discretes.
    
    See Also:
    
    Constant Field Values
  - READ_HOLDING_REGISTERS
```
static final int READ_HOLDING_REGISTERS
```
    Defines a class 1 function code for read holding registers
    
    See Also:
    
    Constant Field Values
  - READ_MULTIPLE_REGISTERS
```
static final int READ_MULTIPLE_REGISTERS
```
    Defines the class 0 function code for read multiple registers. The proper name is "Read Holding Registers".
    
    See Also:
    
    Constant Field Values
  - READ_INPUT_REGISTERS
```
static final int READ_INPUT_REGISTERS
```
    Defines a class 1 function code for read input registers.
    
    See Also:
    
    Constant Field Values
  - WRITE_COIL
```
static final int WRITE_COIL
```
    Defines a class 1 function code for write coil.
    
    See Also:
    
    Constant Field Values
  - WRITE_SINGLE_REGISTER
```
static final int WRITE_SINGLE_REGISTER
```
    Defines a class 1 function code for write single register.
    
    See Also:
    
    Constant Field Values
  - READ_EXCEPTION_STATUS
```
static final int READ_EXCEPTION_STATUS
```
    read exception status Serial devices only.
    
    See Also:
    
    Constant Field Values
  - READ_SERIAL_DIAGNOSTICS
```
static final int READ_SERIAL_DIAGNOSTICS
```
    get serial diagnostics Serial devices only.
    
    See Also:
    
    Constant Field Values
  - READ_COMM_EVENT_COUNTER
```
static final int READ_COMM_EVENT_COUNTER
```
    get comm event counter Serial devices only.
    
    See Also:
    
    Constant Field Values
  - READ_COMM_EVENT_LOG
```
static final int READ_COMM_EVENT_LOG
```
    get comm event log Serial devices only.
    
    See Also:
    
    Constant Field Values
  - WRITE_MULTIPLE_COILS
```
static final int WRITE_MULTIPLE_COILS
```
    Defines a standard function code for write multiple coils.
    
    See Also:
    
    Constant Field Values
  - WRITE_MULTIPLE_REGISTERS
```
static final int WRITE_MULTIPLE_REGISTERS
```
    Defines the class 0 function code for write multiple registers.
    
    See Also:
    
    Constant Field Values
  - REPORT_SLAVE_ID
```
static final int REPORT_SLAVE_ID
```
    Defines a standard function code for read slave ID.
    
    See Also:
    
    Constant Field Values
  - READ_FILE_RECORD
```
static final int READ_FILE_RECORD
```
    read file record
    
    See Also:
    
    Constant Field Values
  - WRITE_FILE_RECORD
```
static final int WRITE_FILE_RECORD
```
    write file record
    
    See Also:
    
    Constant Field Values
  - MASK_WRITE_REGISTER
```
static final int MASK_WRITE_REGISTER
```
    mask write register Update a single register using its current value and an AND and OR mask.
    
    See Also:
    
    Constant Field Values
  - READ_WRITE_MULTIPLE
```
static final int READ_WRITE_MULTIPLE
```
    read / write multiple registers Write some number of registers, then read some number of potentially other registers back.
    
    See Also:
    
    Constant Field Values
  - READ_FIFO_QUEUE
```
static final int READ_FIFO_QUEUE
```
    read FIFO queue Read from a FIFO queue.
    
    See Also:
    
    Constant Field Values
  - READ_MEI
```
static final int READ_MEI
```
    Defines the function code for reading encapsulated data, such as vendor information.
    
    See Also:
    
    Constant Field Values
  - READ_MEI_VENDOR_INFO
```
static final int READ_MEI_VENDOR_INFO
```
    See Also:
    
    Constant Field Values
  - COIL_ON
```
static final int COIL_ON
```
    Defines the byte representation of the coil state on.
    
    See Also:
    
    Constant Field Values
  - COIL_OFF
```
static final int COIL_OFF
```
    Defines the byte representation of the coil state pos.
    
    See Also:
    
    Constant Field Values
  - COIL_ON_BYTES
```
static final byte[] COIL_ON_BYTES
```
    Defines the word representation of the coil state on.
  - COIL_OFF_BYTES
```
static final byte[] COIL_OFF_BYTES
```
    Defines the word representation of the coil state pos.
  - MAX_BITS
```
static final int MAX_BITS
```
    Defines the maximum number of bits in multiple read/write of input discretes or coils (2000).
    
    See Also:
    
    Constant Field Values
  - EXCEPTION_OFFSET
```
static final int EXCEPTION_OFFSET
```
    Defines the Modbus slave exception offset that is added to the function code, to flag an exception.
    
    See Also:
    
    Constant Field Values
  - ILLEGAL_FUNCTION_EXCEPTION
```
static final int ILLEGAL_FUNCTION_EXCEPTION
```
    Defines the Modbus slave exception type illegal function. This exception code is returned if the slave:
    - does not implement the function code or
    - is not in a state that allows it to process the function
    See Also:
    
    Constant Field Values
  - ILLEGAL_ADDRESS_EXCEPTION
```
static final int ILLEGAL_ADDRESS_EXCEPTION
```
    Defines the Modbus slave exception type illegal data address. This exception code is returned if the reference:
    - does not exist on the slave or
    - the combination of reference and length exceeds the bounds of the existing registers.
    See Also:
    
    Constant Field Values
  - ILLEGAL_VALUE_EXCEPTION
```
static final int ILLEGAL_VALUE_EXCEPTION
```
    Defines the Modbus slave exception type illegal data value. This exception code indicates a fault in the structure of the data values of a complex request, such as an incorrect implied length.
    This code does not indicate a problem with application specific validity of the value.
    
    See Also:
    
    Constant Field Values
  - SLAVE_DEVICE_FAILURE
```
static final int SLAVE_DEVICE_FAILURE
```
    Defines the Modbus slave exception type slave device failure. This exception code indicates a fault in the slave device itself.
    
    See Also:
    
    Constant Field Values
  - SLAVE_BUSY_EXCEPTION
```
static final int SLAVE_BUSY_EXCEPTION
```
    Defines the Modbus slave exception type slave busy. This exception indicates the the slave is unable to perform the operation because it is performing an operation which cannot be interrupted.
    
    See Also:
    
    Constant Field Values
  - NEGATIVE_ACKNOWLEDGEMENT
```
static final int NEGATIVE_ACKNOWLEDGEMENT
```
    Defines the Modbus slave exception type negative acknowledgment. This exception code indicates the slave cannot perform the requested action.
    
    See Also:
    
    Constant Field Values
  - GATEWAY_TARGET_NO_RESPONSE
```
static final int GATEWAY_TARGET_NO_RESPONSE
```
    Defines the Modbus slave exception type Gateway target failed to respond. This exception code indicates that a Modbus gateway failed to receive a response from the specified target.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_PORT
```
static final int DEFAULT_PORT
```
    Defines the default port number of Modbus (=502).
    
    See Also:
    
    Constant Field Values
  - MAX_MESSAGE_LENGTH
```
static final int MAX_MESSAGE_LENGTH
```
    Defines the maximum message length in bytes (=256).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_TRANSACTION_ID
```
static final int DEFAULT_TRANSACTION_ID
```
    Defines the default transaction identifier (=0).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_PROTOCOL_ID
```
static final int DEFAULT_PROTOCOL_ID
```
    Defines the default protocol identifier (=0).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_UNIT_ID
```
static final int DEFAULT_UNIT_ID
```
    Defines the default unit identifier (=0).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_VALIDITYCHECK
```
static final boolean DEFAULT_VALIDITYCHECK
```
    Defines the default setting for validity checking in transactions (=true).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_TIMEOUT
```
static final int DEFAULT_TIMEOUT
```
    Defines the default setting for I/O operation timeouts in milliseconds (=3000).
    
    See Also:
    
    Constant Field Values
  - RETRY_SLEEP_TIME
```
static final int RETRY_SLEEP_TIME
```
    Defines the sleep period between transaction retries in milliseconds (=200).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_RECONNECTING
```
static final boolean DEFAULT_RECONNECTING
```
    Defines the default reconnecting setting for transactions (=false).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_RETRIES
```
static final int DEFAULT_RETRIES
```
    Defines the default amount of retires for opening a connection (=3).
    
    See Also:
    
    Constant Field Values
  - DEFAULT_TRANSMIT_DELAY
```
static final int DEFAULT_TRANSMIT_DELAY
```
    Defines the default number of msec to delay before transmission
    Inter-message delays are managed by the SerialTransaction object automatically based on the baud rate. Setting this value to anything other than zero will bypass that process and force a specific inter-message delay (=0).
    
    See Also:
    
    Constant Field Values
  - MINIMUM_TRANSMIT_DELAY
```
static final int MINIMUM_TRANSMIT_DELAY
```
    Defines the default number of msec to delay before transmission if not overridden by DEFAULT_TRANSMIT_DELAY (=2).
    
    See Also:
    
    Constant Field Values
  - INTER_MESSAGE_GAP
```
static final double INTER_MESSAGE_GAP
```
    The number of characters delay that must be maintained between adjacent requests on the same serial port (within the same transaction)
    
    See Also:
    
    Constant Field Values
  - INTER_CHARACTER_GAP
```
static final double INTER_CHARACTER_GAP
```
    The number of characters delay that is the allowed maximum between characters on the same serial port (within the same transaction)
    
    See Also:
    
    Constant Field Values
  - MAX_TRANSACTION_ID
```
static final int MAX_TRANSACTION_ID
```
    Defines the maximum value of the transaction identifier.
    Note: The standard requires that the server copy whatever value the client provides. However, the transaction ID is being limited to signed 16-bit integers to prevent problems with servers that might incorrectly assume the value is a signed value.
    
    See Also:
    
    Constant Field Values
  - SERIAL_ENCODING_ASCII
```
static final String SERIAL_ENCODING_ASCII
```
    Defines the serial encoding "ASCII".
    
    See Also:
    
    Constant Field Values
  - SERIAL_ENCODING_RTU
```
static final String SERIAL_ENCODING_RTU
```
    Defines the serial encoding "RTU".
    
    See Also:
    
    Constant Field Values
  - DEFAULT_SERIAL_ENCODING
```
static final String DEFAULT_SERIAL_ENCODING
```
    Defines the default serial encoding (ASCII).
    
    See Also:
    
    Constant Field Values

Interface Modbus

Field Summary

Field Detail

READ_COILS

READ_INPUT_DISCRETES

READ_HOLDING_REGISTERS

READ_MULTIPLE_REGISTERS

READ_INPUT_REGISTERS

WRITE_COIL

WRITE_SINGLE_REGISTER

READ_EXCEPTION_STATUS

READ_SERIAL_DIAGNOSTICS

READ_COMM_EVENT_COUNTER

READ_COMM_EVENT_LOG

WRITE_MULTIPLE_COILS

WRITE_MULTIPLE_REGISTERS

REPORT_SLAVE_ID

READ_FILE_RECORD

WRITE_FILE_RECORD

MASK_WRITE_REGISTER

READ_WRITE_MULTIPLE

READ_FIFO_QUEUE

READ_MEI

READ_MEI_VENDOR_INFO

COIL_ON

COIL_OFF

COIL_ON_BYTES

COIL_OFF_BYTES

MAX_BITS

EXCEPTION_OFFSET

ILLEGAL_FUNCTION_EXCEPTION

ILLEGAL_ADDRESS_EXCEPTION

ILLEGAL_VALUE_EXCEPTION

SLAVE_DEVICE_FAILURE

SLAVE_BUSY_EXCEPTION

NEGATIVE_ACKNOWLEDGEMENT

GATEWAY_TARGET_NO_RESPONSE

DEFAULT_PORT

MAX_MESSAGE_LENGTH

DEFAULT_TRANSACTION_ID

DEFAULT_PROTOCOL_ID

DEFAULT_UNIT_ID

DEFAULT_VALIDITYCHECK

DEFAULT_TIMEOUT

RETRY_SLEEP_TIME

DEFAULT_RECONNECTING

DEFAULT_RETRIES

DEFAULT_TRANSMIT_DELAY

MINIMUM_TRANSMIT_DELAY

INTER_MESSAGE_GAP

INTER_CHARACTER_GAP

MAX_TRANSACTION_ID

SERIAL_ENCODING_ASCII

SERIAL_ENCODING_RTU

DEFAULT_SERIAL_ENCODING