client-tcp-modbus.py

#!/usr/bin/env python
'''
Pymodbus Synchronous Client

#---------------------------------------------------------------------------# 
# import the various server implementations
#---------------------------------------------------------------------------# 
from pymodbus.client.sync import ModbusTcpClient as ModbusClient

#---------------------------------------------------------------------------# 
# configure the client logging
#---------------------------------------------------------------------------# 
import logging
logging.basicConfig()
log = logging.getLogger()
log.setLevel(logging.DEBUG)

#---------------------------------------------------------------------------# 
# choose the client you want
#---------------------------------------------------------------------------# 
# make sure to start an implementation to hit against. For this
# you can use an existing device, the reference implementation in the tools
# directory, or start a pymodbus server.
#
# If you use the UDP or TCP clients, you can override the framer being used
# to use a custom implementation (say RTU over TCP). By default they use the
# socket framer::
#
#    client = ModbusClient('localhost', port=5020, framer=ModbusRtuFramer)
#
# It should be noted that you can supply an ipv4 or an ipv6 host address for
# both the UDP and TCP clients.
#
# There are also other options that can be set on the client that controls
# how transactions are performed. The current ones are:
#
# * retries - Specify how many retries to allow per transaction (default = 3)
# * retry_on_empty - Is an empty response a retry (default = False)
# * source_address - Specifies the TCP source address to bind to
#
# Here is an example of using these options::
#
#    client = ModbusClient('localhost', retries=3, retry_on_empty=True)
#---------------------------------------------------------------------------# 
client = ModbusClient('129.194.184.124', port=1502)
client.connect()

#---------------------------------------------------------------------------# 
# specify slave to query
#---------------------------------------------------------------------------# 
# The slave to query is specified in an optional parameter for each
# individual request. This can be done by specifying the `unit` parameter
# which defaults to `0x00`
# Room 505: unit=0x05
# Room 507: unit=0x07
# Room 533: unit=0x33
# Room 534: unit=0x34
#
# REGISTERS FOR SAIA 
# http://www.meterbuy.com/fileadmin/user_upload/Data_sheets/120102_SAIA_-_Data_sheet_26-527_EN_DS_Energy-Meter-ALE3-with-Modbus.pdf
# Page 6 -> register_requested = register-1 
#---------------------------------------------------------------------------# 
unit=0x05
count=1
register_requested=36-1
rr = client.read_holding_registers(register_requested, count, unit)

#---------------------------------------------------------------------------# 
# example requests
#---------------------------------------------------------------------------# 
# simply call the methods that you would like to use. An example session
# is displayed below along with some assert checks. Note that some modbus
# implementations differentiate holding/input discrete/coils and as such
# you will not be able to write to these, therefore the starting values
# are not known to these tests. Furthermore, some use the same memory
# blocks for the two sets, so a change to one is a change to the other.
# Keep both of these cases in mind when testing as the following will
# _only_ pass with the supplied async modbus server (script supplied).
#---------------------------------------------------------------------------# 
# rq = client.write_register(1, 10)
# rr = client.read_holding_registers(1,1)
# assert(rq.function_code < 0x80)     # test that we are not an error
# assert(rr.registers[0] == 10)       # test the expected value

#---------------------------------------------------------------------------# 
# close the client
#---------------------------------------------------------------------------# 
client.close()