4-4-3 to 4-4-6 intentionally blanked (for commercial use only)
4-4-7 RESPTIME command
abbrev: RES default: 5 parameter: 0-250
example: RES 5
In the connected packet mode, your TNC must reply to the destination by saying “Yes, I got your
packet”(RR frame) after the information (I frame) is correctly received. Up to 7 RR frames can be
sent together at one time. For example, you can reduce the RR frame transmission during a file
transaction when different I frames are received frequently. This command sets the waiting time
between the reception of an I frame and transmission of a RR frame in units of 100 ms. The
communication efficiency may become poor if a higher number is set as the time delay to send
RR becomes longer. If an even higher number is set, an I frame may be sent before an RR frame
is sent.
4-4-8 FRACK command
abbrev. FR default: 3 parameter: 0-250
example: FR 5
When you are “on-line” (connected) and the transmitted information frame (I frame) is received at
its destination correctly, you receive a “Yes, I got it” (RR frame). If a certain time has elapsed but
you still don’t get a reply, the I frame will be transmitted again (retry feature). Beside I frames,
and a connection request frame (SABM frame), there are frames that require a reconfirmation
from the destination. The retry will take place if a reply is not received. This command sets the
time duration between the end of transmission of the reply-required signal and the start time of a
retry transmission in 1 second.
When a relay station is involved, it automatically waits for a [(number of relay stations X 2 + 1) X
parameter] period. The relay stations only pass the messages, and they do not acknowledge each
packet. Accordingly, the transmitted packet takes some time until it gets to the destination and a
reply comes back.
This unit automatically changes the retry fraction time in accordance with the number of relay
stations. In case the packet traffic is very high, set this parameter a little higher than the default.
It eliminates unnecessary retries when traffic is reduced.
4-4-9 RETRY command
abbrev. RE default 10 parameter: 0-15
example: RE 15
This command is used to set the maximum number of retries. When the maximum number of
retries exceeds the parameter, [****** retry count exceeded],[***** DISCONNECTED] appears on
the screen, and the TNC returns to the disconnected state. The conventional TNC AX.25 protocol
may transmit a SABM frame at this point, and the RELINK command (default OFF) is available
to set this option. The EJ-41U does not have this parameter (fixed at OFF position).