Allocation of Front End II interface compliant device - redhawksdr

Question

I am working REDHAWK 1.9 on Centos 6.4 (32 bit) OS.
I have a device that conforms to the FrontEnd( FE) II interface for a Tuner. The allocation of an FEII compliant device is via a structure (frontend_tuner_allocation). The IDE does not appear to allow to define this allocation on the implementations tab.
I looked at REDHAWK UHD device usage. It describes how to make the necessary connections but I didn't see how to allocate via the tuner allocation structure.
I have seen example (offline) where to do this allocation the allocation structure has to be hand coded into the xml file. I saw in one case this was done in the components spd.xml file. I have another example where it was done in the waveform.
example 1:
In components spd.xml
<usesdevice id="DCE:11bafc63-d8ce-428b-8b4e-39cb96034e8c" type="usesDevice">
<propertyref refid="DCE:cdc5ee18-7ceb-4ae6-bf4c-31f983179b4d" value="FRONTEND:TUNER"/>
<structref refid="FRONTEND::tuner_allocation">
<simpleref refid="FRONTEND::tuner_allocation::allocation_id" value="SimFE2TestSink"/>
<simpleref refid="FRONTEND::tuner_allocation::center_frequency" value="857000000.0"/>
</structref>
</usesdevice>
example 2:
In waveform spd.xml
<usesdevicedependencies>
<usesdevice id="DCE:93a650f5-719f-4dc3-8143-fd438b94c19f" type="usesXX">
<propertyref refid="DCE:cdc5ee18-7ceb-4ae6-bf4c-31f983179b4d" value="FRONTEND::TUNER"/>
<structref refid="FRONTEND::tuner_allocation">
<simpleref refid="FRONTEND::tuner_allocation::tuner_type" value="RX_DIGITIZER_CHANNELIZER"/>
<simpleref refid="FRONTEND::tuner_allocation::allocation_id" value="XXDevice"/>
<simpleref refid="FRONTEND::tuner_allocation::center_frequency" value="100000000"/>
<simpleref refid="FRONTEND::tuner_allocation::bandwidth" value="128000"/>
<simpleref refid="FRONTEND::tuner_allocation::sample_rate" value="256000"/>
<simpleref refid="FRONTEND::tuner_allocation::group_id" value=""/>
<simpleref refid="FRONTEND::tuner_allocation::rf_flow_id" value=""/>
</structref>
</usesdevice>
</usesdevicedependencies>
How is the best way to allocate FrontEnd Tuner?

Answer 1

There isn't really a 'best' way to allocate a frontend tuner device. It really just depends on which way makes the most sense for your specific scenario.
The two examples you provided are valid ways of allocating a frontend tuner via XML, but there's another option (using python) that may help clarify what is going on under the hood.
Assuming your device is already running:
from ossie.utils import redhawk
from ossie.cf import CF
# Attach to the domain
domain = redhawk.attach("REDHAWK_DEV")
# Locate your FEI device
myFEIDevice = None
for device in domain.devices:
if device.name == "myFEIDevice":
myFEIDevice = device
# Sanity check
if not myFEIDevice:
raise Exception("Unable to locate myFEIDevice!")
At this point, your FEI device should accept an allocateCapacity(tunerRequestProps) call:
from ossie.utils import uuid
# Setup tuning variables
allocationId = str(uuid.uuid4())
tunerType = "RX_DIGITIZER_CHANNELIZER"
centerFreq = 100e6
sampleRate = 48000.0
sampleRateTol = 10.0
bandwidth = 16000.0
bandwidthTol = 10.0
deviceControl = False
groupId = ""
rfFlowId = ""
# Setup allocation request properties
props = []
props.append(CF.DataType("FRONTEND::tuner_allocation::tuner_type", tunerType))
props.append(CF.DataType("FRONTEND::tuner_allocation::allocation_id", allocationId))
props.append(CF.DataType("FRONTEND::tuner_allocation::center_frequency", centerFreq))
props.append(CF.DataType("FRONTEND::tuner_allocation::bandwidth", bandwidth))
props.append(CF.DataType("FRONTEND::tuner_allocation::bandwidth_tolerance", bandwidthTol))
props.append(CF.DataType("FRONTEND::tuner_allocation::sample_rate", sampleRate))
props.append(CF.DataType("FRONTEND::tuner_allocation::sample_rate_tolerance", sampleRateTol))
props.append(CF.DataType("FRONTEND::tuner_allocation::device_control", deviceControl))
props.append(CF.DataType("FRONTEND::tuner_allocation::group_id", groupId))
props.append(CF.DataType("FRONTEND::tuner_allocation::rf_flow_id", rfFlowId))
# Setup tuner request struct properties
fe_alloc_props = {}
fe_alloc_props["FRONTEND::tuner_allocation"] = props
# Attempt to allocate your device
allocationResult = myFEIDevice.allocateCapacity(fe_alloc_props)
At this point, if the allocation was successful, you should see the allocation request is now represented in the device's frontend_tuner_status property