RS485 signal collision

[admin]

port:read(17) is a blocking read. It won't return until 17 bytes are read.
For one-way communication you can use UDP for data transport between scripts:

Code:

if not server then
  require('socket')
  server = socket.udp()
  server:setsockname('127.0.0.1', 5485)
  server:settimeout(60)
end

if not port then
  require('serial')
  port = serial.open('/dev/RS485-1', {
    baudrate = 19200,
    databits = 8,
    stopbits = 1,
    parity = 'none',
    duplex = 'half'
  })
end

data = server:receive()
if data then
  port:write(data)
  os.sleep(1)
  port:write(':RR\r\n')
end

Send commands like this:

Code:

data = '123456'

sock = require('socket').udp()
sock:sendto(data, '127.0.0.1', 5485)
sock:close()