nan for time in CDC hit

["Mark M. Ito" <marki@jlab.org>]

Folks,

I'm seeing an event where the CDC reports a time of nan (not a number). 
Here is the HDDM excerpt:

      <centralDC>
        <cdcStraw ring="1" straw="12">
          <cdcStrawHit dE="7.5412e-06" t="122.82" />
        </cdcStraw>
        <cdcStraw ring="2" straw="14">
          <cdcStrawHit dE="1.21206e-05" t="116.647" />
        </cdcStraw>
        <cdcStraw ring="3" straw="16">
          <cdcStrawHit dE="8.583e-06" t="121.42" />
        </cdcStraw>
        <cdcStraw ring="4" straw="14">
          <cdcStrawHit dE="8.63163e-06" t="132.226" />
        </cdcStraw>
        <cdcStraw ring="5" straw="16">
          <cdcStrawHit dE="3.73797e-06" t="nan" />
        </cdcStraw>
        <cdcTruthPoint dEdx="1.6289e-06" dradius="0.664746" 
phi="1.66781" primary="1" ptype="0" px="0" py="0" pz="0" r="10.885" 
t="0" track="1" z="122.517" />
        <cdcTruthPoint dEdx="2.35889e-06" dradius="0.629031" 
phi="1.68274" primary="1" ptype="0" px="0" py="0" pz="0" r="12.6595" 
t="0" track="1" z="131.927" />
        <cdcTruthPoint dEdx="1.78787e-06" dradius="0.653524" 
phi="1.69816" primary="1" ptype="0" px="0" py="0" pz="0" r="14.4291" 
t="0" track="1" z="141.334" />
        <cdcTruthPoint dEdx="1.87613e-06" dradius="0.709273" 
phi="1.73119" primary="1" ptype="0" px="0" py="0" pz="0" r="18.1297" 
t="0" track="1" z="161.007" />
        <cdcTruthPoint dEdx="1.80763e-06" dradius="nan" phi="nan" 
primary="1" ptype="0" px="0" py="0" pz="0" r="nan" t="0" track="1" 
z="nan" />
      </centralDC>

Does anyone know if this is a bug or a feature?

The one-event HDDM file is posted at 
http://www.jlab.org/~marki/misc/event2.hddm .

  -- Mark