RS485 signal collision

[admin]

Ok then the script is already more or less correct. Use this to add an alert if 5 timeouts in a row happen.

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'
  })

  timeouts = 0
end

data = server:receive()
if data then
  port:write(data)
  os.sleep(0.5)
end

port:flush()
port:write(':RR\r\n')
data, err = port:read(17, 1) -- read 17 bytes for up to 1 second

if data and #data == 17 then
  timeouts = 0
  -- parse data response here
else
  timeouts = timeouts + 1

  if timeouts == 5 then
    -- send alert
  end
end