I am writing a scada package that has a significant amount of user
defined parameters stored in text files that I wish to cleanly access
in code. By way of an example, a few lines from the configuration file
would typically be ...
[Plant Outputs]
Y0 P1 Pump 1 Pressure
Y1 P2 Pump 2 Fluid Transfer Pump
Y2 P3 Pump 3 Vac Pump
Y3 P4 Pump 4 Vac Pump
Y4 P5 Pump 5 / Pump 1B
Y5 P6 Pump 6 / Pump 2B
Y6 M
Y7 D
Y10 E
Y11 F
I can read these values in as dictionary items and refernce them in
code like this...
Y['P4'] = 1 # Which will ultimately switch my pump on
Y['P3'] = 0 # Which will ultimately switch my pump off
but I would much rather reference the plant outputs like this ...
Y.P4 = 1
Y.P3 = 0
basically it makes it easier for third parties to code, also my IDE
(wing) is able to use intellisense to determine exactly which Y outputs
have been loaded during code configuration.
Now I can achieve this by loading the configuration parameters in a
class like this...
class c_y:
def __init__(self):
self.P1 = 0
self.P2 = 0
self.P3 = 0
self.P4 = 0
so I can do
Y = c_y()
Y.P4 = 1
Y.P3 = 0
etc
However, what I really would like is something like...
class c_y:
def __init__(self):
self.P1 = [0, 'OB1', 0 ]
self.P2 = [0, 'OB1', 1 ]
self.P3 = [0, 'OB1', 2 ]
self.P4 = [0, 'OB1', 3 ]
Because that way I can also hold binary loadings and data register
(this is a PLC application) references which give me full information
for handling the pump bits.
However, this means that I have to access the pump status bits like
this...
Y.P4[0] = 1
Y.P3[0] = 0
Which takes me away from the clean code
Y.P4 = 1
Y.P3 = 0
That I would like to have.
Can anyone suggets a technique for parameter storage that may be able
to give me what I want here ?
Thanks in advance.
David
--
http://mail.python.org/mailman/listinfo/python-list
