PySignalSimulator Device Server

This Python Device Server will allow to declare dynamic attributes which values will depend on a given time-dependent formula:

To specify the code for each attribute we use python that has several advantages:

• No compilation of code; just write, refresh() and see the result.
• Easy syntax (users can tune it).
• We can control what can be executed (we use a restricted python eval that only loads the modules/libraries we are interested in).

Example of DynamicAttributes property declaration

The attributes are created after restarting the device or calling updateDynamicAttributes() ... do not use Init() to do it!

  Square=0.5+square(t) #(t = seconds since the device started)
  NoisySinus=2+1.5*sin(3*t)-0.5*random()
  SomeNumbers=DevVarLongArray([1000.*i for i in range(1,10)])\

  TEMPERATURE = 25+5*sin((1./60)*t)
  PRESSURE = 2.5e-5+1e-6*sin((1./60)*t)
  TEMPERATURES = DevVarDoubleArray([25+v*sin((1./k)*t) for v,k in [(5,60),(10,30),(15,45),(5,5)]])

  MAX_TEMPERATURE = max(TEMPERATURES)
  TEMP_LIMIT = READ and VAR('TEMP_LIMIT') or WRITE and VAR('TEMP_LIMIT',VALUE)

  HOT = DevBoolean(MAX_TEMPERATURE>VAR('TEMP_LIMIT'))
  COLD = DevBoolean(MAX_TEMPERATURE<15)
  TEMPERATE = DevBoolean(not HOT and not COLD)
  EXTREME = DevBoolean(HOT or COLD)

Right part of equality is the attribute name, type is DevDouble? by default but all tango types are available. READ,WRITE,VALUE,t,ATTR(),VAR() are reserved keywords to manage READ/WRITE access, time, external attribute reading and storing variables to be used in other attributes.

Format is specified at  tango-controls.org

Signals that can be easily generated with amplitude between 0.0 and 1.0 are:

rampt(t), sin(t), cos(t), exp(t), triangle(t), square(t,duty), random()

The MaxValue/MinValue property for each Attribute will determine the State of the Device only if the property DynamicStates is not defined.

If defined, DynamicStates will use this format:

  FAULT=2*square(0.9,60)>0.<br>
  ALARM=NoisySinus>3<br>
  ON=1<br>

This device inherits from PyTango_utils.dynamic.DynamicDS Class