Service manual

DATA INTERFACE DESCRIPTION
A-9
April 2001
Part No. 001-9800-203
2. The modem must assert the DATA PTT line for
transmission of any ACKs or NACKs. During this
time the radio does not encode any subaudible data.
3. The modem must release the DATA PTT line for the
reception of any more data. During this time the
radio decodes subaudible data.
4. For all subsequent release-to-assert transitions on
the DATA PTT line, the radio transmits without
encoding sub-audible data.
5. For all subsequent assert to release transitions on the
DATA PTT line, the radio receives and decodes
subaudible data.
6. The data session is completed by the release of the
DATA ARQ line.