HOST
30
HF Mode operation
When using a non-packet mode on the HF port of the
KAM
, received HF data will be sent to the
host with status byte 'D', ort byte '2' and stream byte '0'. Each received character is sent from the
KAM
to the host in a separate block.
When operating AMTOR mode A, another
KAM
to host block is possible, indicating the current sta-
tus of your station (IRS or ISS). This block has a status byte of 'I', port byte '2' and the stream
byte indicates IRS ('0') or ISS ('1'). This block will be sent whenever there is a change.
When operating in the AMTOR mode A (ARQ) the
KAM
will send an 'S' block containing information
pertinent to the link. For instance, when the link is established, the
KAM
sends an 'S' with the mes-
sage <LINKED> or <LINED to xxxxxxx>. 'S' frames are also sent indicating a link failure, or any-
time the KAM returns to AMTOR STANDBY. This can occur when the other station breaks the link,
or if the link fails due the poor propagation.
When receiving NAVTEX, the
KAM
does not send any information to the host until it received a
proper NAVTEX header for a message that is eligible to be printed (see the NAVTEX section of the
operating manual). When the header is received (ZCZC XXNN) this header will be sent to the host
in a single block. After the closing NNNN of the message, if the number of errors received exceeds
the NAVERR setting, an error message will be sent from the
KAM
to the host indicating "*** TOO
MANY ERRORS" and the message number. This will be sent as a 'D20' frame and not as a status
frame. This allows this message to be stored in the file if you are capturing the HF channel to disk.
This message will also be sent if the link fails before the closing of the current message.
