MTConnect Adapter acting as a relay for a physical device (e.g. a sensor) sending SHDR data on the serial port.
The MTCAdapterReay allows to hock up a device capable of sending SHDR data on the serial port but not capable of sending TCP/IP data to an MTConnect Agent.
The MTCAdapterRelay is a small Python library desinged to work together with the MTConnect cpp agent.
Two classes need to be defined: an MTCAdapterRelayHandler and a MTCAdapterRelay class.
The MTCAdapterRelayHandler is responsible to define the proper parameters for communicating with the
device over the serial port.
At minimum the 'serial_port' attribute must be defined. It is the name of the Linux device file
to access the serial port (e.g. /dev/ttyUSB1).
Further the following attributes may have to be redfined to match the configuration of the used serial port:
baudrate = 115200
parity = serial.PARITY_NONE
bytesize = serial.EIGHTBITS
stopbits = serial.STOPBITS_ONE
The MTCAdapterRelay class is a specialized TCP/IP server which implements the PING/PONG hearthbeat convention of
the MTConnect cpp agent.
The attribute adapter_port (default value 7878) holds the port number on which the adapter relay will run.
The attribute deviceHandler_class must contain the MTCAdapterRelayHandler class defining the correct
serial port paramters to communicate with the device.
A typical example looks like this (this is an example for a temperature sensor connected via an Arduino type device. The Arduino sketch is availble here):
from mtcadapterrelay import MTCAdapterRelay, MTCAdapterRelayHandler
import sys
class DS18B20_MTCAdapterRelayHandler(MTCAdapterRelayHandler):
serial_port = '/dev/ttyUSB1'
baudrate = 115200
parity = serial.PARITY_NONE
bytesize = serial.EIGHTBITS
stopbits = serial.STOPBITS_ONE
class DS18B20_MTCAdapterRelay(MTCAdapterRelay):
adapter_port = 8881
deviceHandler_class = DS18B20_MTCAdapterRelayHandler
myAdapter = DS18B20_MTCAdapterRelay()
try:
myAdapter.serve_forever()
except KeyboardInterrupt:
sys.exit(0)