`constants` — Modbus Default Values¶

Module author: Galen Collins <bashwork@gmail.com>

Section author: Galen Collins <bashwork@gmail.com>

API Documentation¶

This is the single location for storing default values for the servers and clients.

class pymodbus.constants.Defaults¶

A collection of modbus default values

Retries¶: The default number of times a client should retry the given request before failing (3)

Timeout¶: The default amount of time a client should wait for a request to be processed (3 seconds)

Reconnects¶: The default number of times a client should attempt to reconnect before deciding the server is down (0)

ProtocolId¶: The modbus protocol id. Currently this is set to 0 in all but proprietary implementations.

Baudrate¶: The speed at which the data is transmitted over the serial line. This defaults to 19200.

Parity¶

The type of checksum to use to verify data integrity. This can be on of the following:

- (E)ven - 1 0 1 0 | P(0)
- (O)dd  - 1 0 1 0 | P(1)
- (N)one - 1 0 1 0 | no parity

This defaults to (N)one.

Bytesize¶: The number of bits in a byte of serial data. This can be one of 5, 6, 7, or 8. This defaults to 8.

Stopbits¶: The number of bits sent after each character in a message to indicate the end of the byte. This defaults to 1.

class pymodbus.constants.ModbusStatus¶

These represent various status codes in the modbus protocol.

Waiting¶: This indicates that a modbus device is currently waiting for a given request to finish some running task.

Ready¶: This indicates that a modbus device is currently free to perform the next request task.