NEWS.md

2011-08-10 Release 1.0.4

1. Fixed issue #11

2011-07-17 Release 1.0.3

1. Fixed issue #10
2. Added new options for TCPServer#new and RTUViaTCPServer#new :host - ip of host server (default 127.0.0.1) :max_connection - maximum (client default 4)

2011-07-1 Release 1.0.2

1. Fixed issue #9

2011-06-30 Release 1.0.1

1. Fixed issue #8

2011-06-27 Release 1.0.0

New API for client part of library

Example:

require 'rmodbus'

ModBus::TCPClient.new('127.0.0.1', 8502) do |cl|
  cl.with_slave(1) do |slave|
    # Read a single holding register at address 16
    slave.holding_registers[16]

    # Write a single holding register at address 16
    slave.holding_registers[16] = 123

    # Read holding registers 16 through 20
    slave.holding_registers[16..20]

    # Write holding registers 16 through 20 with some values
    slave.holding_registers[16..20] = [1, 2, 3, 4, 5]
  end
end

for more information see

Conversion to/from 32bit registers

Some modbus devices use two registers to store 32bit values. RModbus provides some helper functions to go back and forth between these two things when reading/writing. The built-in examples assume registers in a particular order but it's trivial to change.

# Reading values in multiple registers (you can read more than 2 and convert them all so long as they are in multiples of 2)
res = slave.holding_registers[0..1]
res.inspect => [20342, 17344]
res.to_32i => [1136676726]
res.to_32f => [384.620788574219]

# Writing 32b values to multiple registers
cl.holding_registers[0..1] = [1136676726].from_32i
cl.holding_registers[0..1] => [20342, 17344]
cl.holding_registers[2..3] = [384.620788574219].from_32f
cl.holding_registers[2..3] => [20342, 17344]

Support JRuby

Now you could use RModBus on JRuby without RTU implementation.

RTU classes requires gem serialport which currently not compatible with JRuby