fixed bug that I did that was noted by allan willcox

diff --git a/demo/ao_waveform.c b/demo/ao_waveform.c
index 11f82d7cc60c150c01681dc889d1cb3c4f26a5f9..d24428922a890ecaed3bab13c47a2437d28ddbb0 100644 (file)
--- a/demo/ao_waveform.c
+++ b/demo/ao_waveform.c
@@ -142,6 +142,7 @@ int main(int argc, char *argv[])
        
        memset(&insn, 0, sizeof(comedi_insn));
        insn.insn = INSN_INTTRIG;
+       insn.subdev = subdevice;
        comedi_do_insn(dev, &insn);
 
        while(1){