Since I set up a schedule of burst hardware injections last night, three of the scheduled injection times have passed.

The first one, at GPS 1126160499 (injection start at 1126160499, actual burst signal centered at 1126160500), should have been executed at H1 (not at L1 since it was down at the time), but didn't work.  The tinjburst.log file says: "1126160499.000000 hwinj_1126160499_2_ 1.00e+00 Compromised".  (It says that five times, because tinj retries a few times if it initially fails.)  The more verbose tinj.log says:
Injection imminent in ~297s...
  1126160499 2 1 hwinj_1126160499_2_
GRB alert at 1126151534: injection allowed.
Detector locked.
Intent bit is on.
calling awgstream...
  awgstream H1:CAL-INJ_TRANSIENT_EXC 16384.000000 ../config/Burst/Waveform/hwinj_1126160499_2_H1.txt 1.000000 1126160499.000000
awgstream failure: injection compromised!

That's strange... Maybe it has to do with environment variables.  I seem to be able to run awgstream fine from the command line in an interactive session, with this zero-amplitude test while H1 was down:
[hinj@h1hwinj1 tinj]$ awgstream H1:CAL-INJ_TRANSIENT_EXC 16384.000000 ../config/Burst/Waveform/hwinj_1126160499_2_H1.txt 0.0 1126187950.000000
Channel = H1:CAL-INJ_TRANSIENT_EXC
File    = ../config/Burst/Waveform/hwinj_1126160499_2_H1.txt
Scale   =          0.000000
Start   = 1126187950.000000
The fact that a zero-amplitude injection succeeded rules out a problem with awg.

I tried to do another test by adding a zero-amplitude injection to the schedule at GPS 1126191200, but since the detector was not locked, tinj did not even call awgstream, so I didn't learn anything from that.

The second and third scheduled injections, at GPS 1126180499 (injection start at 1126180499, actual burst signal centered at 1126180500) and 1126190499, did not occur because the detector was not in observing mode at either time; that's the correct behavior.