pyprofibus/examples/example_s7_315_2dp.py

#!/usr/bin/env python3
#
# Simple pyprofibus example
#
# This example initializes an S7-315-2DP configured as slave,
# reads its input data and writes the data back to the module.
#

import sys
sys.path.insert(0, "..")
import pyprofibus

def main(confdir=".", watchdog=None):
	master = None
	try:
		# Parse the config file.
		config = pyprofibus.PbConf.fromFile(confdir + "/example_s7_315_2dp.conf")

		# Create a DP master.
		master = config.makeDPM()

		# Create the slave descriptions.
		outData = {}
		for slaveConf in config.slaveConfs:
			slaveDesc = slaveConf.makeDpSlaveDesc()

			# Register the S7-315-2DP slave at the DPM
			master.addSlave(slaveDesc)

			# Set initial output data.
			outData[slaveDesc.slaveAddr] = bytearray((0x00, ))

		# Initialize the DPM
		master.initialize()

		# Cyclically run Data_Exchange.
		while True:
			# Write the output data.
			for slaveDesc in master.getSlaveList():
				slaveDesc.setMasterOutData(outData[slaveDesc.slaveAddr])

			# Run slave state machines.
			handledSlaveDesc = master.run()

			# Get the in-data (receive) and set it as out-data (transmit).
			if handledSlaveDesc:
				inData = handledSlaveDesc.getMasterInData()
				if inData is not None:
					# In our example the output data shall be a mirror of the input.
					outData[handledSlaveDesc.slaveAddr] = inData

			# Feed the system watchdog, if it is available.
			if watchdog is not None:
				watchdog()

	except pyprofibus.ProfibusError as e:
		print("Terminating: %s" % str(e))
		return 1
	finally:
		if master:
			master.destroy()
	return 0

if __name__ == "__main__":
	import sys
	sys.exit(main())