Class: ModBus::Client

Inherits:
Object
  • Object
show all
Includes:
Errors
Defined in:
lib/rmodbus/client.rb

Direct Known Subclasses

TCPClient

Constant Summary collapse

CONNECTION_RETRIES =

Number of times to retry on connection and read timeouts

10
READ_RETRIES = 
10

Instance Method Summary collapse

Instance Method Details

#mask_write_register(addr, and_mask, or_mask) ⇒ Object

Write *current value & and_mask | or mask in addr register

Return self



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# File 'lib/rmodbus/client.rb', line 193

def mask_write_register(addr, and_mask, or_mask)
  query("\x16" + addr.to_bytes + and_mask.to_bytes + or_mask.to_bytes)
  self  
end

#query(pdu) ⇒ Object 



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# File 'lib/rmodbus/client.rb', line 198

def query(pdu)    
  send_pdu(pdu)

  tried = 0
  begin
    timeout(1, ModBusTimeout) do
      pdu = read_pdu
    end
  rescue ModBusTimeout => err
    tried += 1
    retry unless tried >= READ_RETRIES
    raise ModBusTimeout.new, 'Timed out during read attempt'
  end

  if pdu[0].to_i >= 0x80
    case pdu[1].to_i
      when 1
        raise IllegalFunction.new, "The function code received in the query is not an allowable action for the server"  
      when 2
        raise IllegalDataAddress.new, "The data address received in the query is not an allowable address for the server"
      when 3
        raise IllegalDataValue.new, "A value contained in the query data field is not an allowable value for server"
      when 4
        raise SlaveDeviceFailure.new, "An unrecoverable error occurred while the server was attempting to perform the requested action"
      when 5
        raise Acknowledge.new, "The server has accepted the request and is processing it, but a long duration of time will be required to do so"
      when 6
        raise SlaveDeviceBus.new, "The server is engaged in processing a long duration program command"
      when 8
        raise MemoryParityError.new, "The extended file area failed to pass a consistency check"
      else
        raise ModBusException.new, "Unknown error"
    end
  end
  pdu[2..-1]
end

#read_coils(addr, ncoils) ⇒ Object

Read value ncoils coils starting with addr

Return array of their values



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# File 'lib/rmodbus/client.rb', line 99

def read_coils(addr, ncoils)
  query("\x1" + addr.to_bytes + ncoils.to_bytes).to_array_bit[0..ncoils-1]
end

#read_discret_inputs(addr, ncoils) ⇒ Object

Deprecated version of read_discrete_inputs



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# File 'lib/rmodbus/client.rb', line 111

def read_discret_inputs(addr, ncoils)
  warn "[DEPRECATION] `read_discret_inputs` is deprecated.  Please use `read_discrete_inputs` instead."
  read_discrete_inputs(addr, ncoils)
end

#read_discrete_inputs(addr, ncoils) ⇒ Object

Read value ncoils discrete inputs starting with addr

Return array of their values



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# File 'lib/rmodbus/client.rb', line 106

def read_discrete_inputs(addr, ncoils)
  query("\x2" + addr.to_bytes + ncoils.to_bytes).to_array_bit[0..ncoils-1]
end

#read_holding_registers(addr, nreg) ⇒ Object

Read value nreg holding registers starting with addr

Return array of their values



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# File 'lib/rmodbus/client.rb', line 119

def read_holding_registers(addr, nreg) 
  query("\x3" + addr.to_bytes + nreg.to_bytes).to_array_int16
end

#read_input_registers(addr, nreg) ⇒ Object

Read value nreg input registers starting with addr

Return array of their values



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# File 'lib/rmodbus/client.rb', line 126

def read_input_registers(addr, nreg)
  query("\x4" + addr.to_bytes + nreg.to_bytes).to_array_int16
end

#write_multiple_coils(addr, val) ⇒ Object

Write val in coils starting with addr

val it is array of bits

Return self



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# File 'lib/rmodbus/client.rb', line 157

def write_multiple_coils(addr, val)
  nbyte = ((val.size-1) >> 3) + 1
  sum = 0
  (val.size - 1).downto(0) do |i|
    sum = sum << 1
    sum |= 1 if val[i] > 0
  end
   
  s_val = ""
  nbyte.times do
    s_val << (sum & 0xff).chr
    sum >>= 8 
  end

  query("\xf" + addr.to_bytes + val.size.to_bytes + nbyte.chr + s_val)
  self
end

#write_multiple_registers(addr, val) ⇒ Object

Write val in registers starting with addr

val it is array of integer

Return self



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# File 'lib/rmodbus/client.rb', line 180

def write_multiple_registers(addr, val)
  s_val = ""
  val.each do |reg|
    s_val << reg.to_bytes
  end

  query("\x10" + addr.to_bytes + val.size.to_bytes + (val.size * 2).chr + s_val)
  self
end

#write_single_coil(addr, val) ⇒ Object

Write val in addr coil

if val lager 0 write 1

Return self



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# File 'lib/rmodbus/client.rb', line 135

def write_single_coil(addr, val)
  if val == 0
    query("\x5" + addr.to_bytes + 0.to_bytes)
  else
    query("\x5" + addr.to_bytes + 0xff00.to_bytes) 
  end
  self
end

#write_single_register(addr, val) ⇒ Object

Write val in addr register

Return self



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# File 'lib/rmodbus/client.rb', line 147

def write_single_register(addr, val)
  query("\x6" + addr.to_bytes + val.to_bytes)
  self
end