This variable indicates what type of code is
being sent across the DS1 circuit by the CSU. The
values mean:
ds1SendNoCode sending looped or normal data
ds1SendSetCode sending a loopback request
ds1SendResetCode sending a loopback termination request
ds1SendQRSS sending the BERT pattern described in
ANSI T1.403-1989 section 5.6
ds1OtherTest sending a different BERT/BLERT pattern,
such as all zeroes, all ones, etc.