1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
#!/usr/bin/env python
'''
Pymodbus Server With Custom Datablock Side Effect
--------------------------------------------------------------------------
This is an example of performing custom logic after a value has been
written to the datastore.
'''
#---------------------------------------------------------------------------#
# import the modbus libraries we need
#---------------------------------------------------------------------------#
from pymodbus.server.async import StartTcpServer
from pymodbus.device import ModbusDeviceIdentification
from pymodbus.datastore import ModbusSparseDataBlock
from pymodbus.datastore import ModbusSlaveContext, ModbusServerContext
from pymodbus.transaction import ModbusRtuFramer, ModbusAsciiFramer
#---------------------------------------------------------------------------#
# configure the service logging
#---------------------------------------------------------------------------#
import logging
logging.basicConfig()
log = logging.getLogger()
log.setLevel(logging.DEBUG)
#---------------------------------------------------------------------------#
# create your custom data block here
#---------------------------------------------------------------------------#
class CustomDataBlock(ModbusSparseDataBlock):
''' A datablock that stores the new value in memory
and performs a custom action after it has been stored.
'''
def setValues(self, address, value):
''' Sets the requested values of the datastore
:param address: The starting address
:param values: The new values to be set
'''
super(ModbusSparseDataBlock, self).setValues(address, value)
# whatever you want to do with the written value is done here,
# however make sure not to do too much work here or it will
# block the server, espectially if the server is being written
# to very quickly
print "wrote {} to {}".format(value, address)
#---------------------------------------------------------------------------#
# initialize your data store
#---------------------------------------------------------------------------#
block = CustomDataBlock()
store = ModbusSlaveContext(di=block, co=block, hr=block, ir=block)
context = ModbusServerContext(slaves=store, single=True)
#---------------------------------------------------------------------------#
# initialize the server information
#---------------------------------------------------------------------------#
identity = ModbusDeviceIdentification()
identity.VendorName = 'pymodbus'
identity.ProductCode = 'PM'
identity.VendorUrl = 'http://github.com/bashwork/pymodbus/'
identity.ProductName = 'pymodbus Server'
identity.ModelName = 'pymodbus Server'
identity.MajorMinorRevision = '1.0'
#---------------------------------------------------------------------------#
# run the server you want
#---------------------------------------------------------------------------#
p = Process(target=device_writer, args=(queue,))
p.start()
StartTcpServer(context, identity=identity, address=("localhost", 5020))
|
