MFJ MFJ-1270C, Системное руководство

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MFJ-1270C/1274C MANUAL COMMANDS
Page 176
Parameters:
ON The MFJ TNC will send data to the terminal in RXBLOCK
format.
OFF The MFJ TNC will send data to the terminal in standard
format.
RXBLOCK is designed for automated operations, such as packet bulletin board
stations. It is intended to help such systems discriminate between data received
from the connected station and MFJ TNC-generated messages.
Correct operation of
RXBLOCK is dependent on the AWLEN parameter getting
set to 8 (bits) since the character FF hex marks the beginning of a received data
unit header.
When
RXBLOCK is ON , data from other stations will be sent from the MFJ TNC
in the following format:
-----------------------------------------------------------------------------------------------
| $FF L0 L1 PID DATA |
-----------------------------------------------------------------------------------------------
(prefix) (length) (pid) (data)
The fields above are defined as follows:
prefix $FF
= A character with all 8 bits set
length L0 = The high order length of the data, length, and pid fields
logically ORed with the value $F0
L1 = The low order length of the data, length, and pid fields
pid PID = The Protocol IDentifier byte received for the following data
field
data DATA =[Optional], variable length data
For best operation it is suggested that parameters like
AUTOLF , MFILTER etc.
be set OFF in order to prevent uncertainties in the size of the data field.
RXCAL Mode: All IMMEDIATE