Epson MFJ-1278B manual Special Protocol Timing, Monitor Functions

MFJ-1278B MULTI-MODE ADVANCED OPERATION

signals up to 9600 baud, but an external modem is required for operation above 1200 baud. An optional 2400 bps PSK modem board is available from MFJ Enterprises, Inc. This 2400 bps PSK modem board can be installed inside the MFJ-1278B. Radio data rate of 2400/9600 is selectable with software command by the MFJ-1278B. When an external modem is installed and when it is in selected to operate the TURBO LED on the front panel of the MFJ-1278B will light. Contact MFJ Enterprises, Inc. for more detail. For installation of an external modem, see APPENDIX F in this manual for more details.

Special Protocol Timing

You can set up a connection time-out with the command CHECK, which specifies a time in multiples of 10-second intervals. This function prevents the MFJ-1278B from getting stuck in a connection when the other station disappears for longer than the specified time. The MFJ- 1278B uses this time somewhat differently depending on the setting of AX25L2V2.

The command RESPTIME sets a delay between the receipt of a packet and the transmission of the acknowledgment packet. This delay is used to prevent collisions between an acknowledgment and another packet from the sending station. This is primarily necessary during file transfers; otherwise the delay is best set to 0. During file transfers the stations receiving the file should set RESPTIME to 10 or 12 (default).

The timing of packet transmission in Transparent Mode is determined by the command PACTIME. You can choose the way packet transmission is timed. If you are typing input to a remote computer it is usually best to have packets transmitted at regular intervals. If your computer is operating a remote-host or bulletin board program you should send packets after an interval with no further input from the computer. You can enable the use of PACTIME in Converse Mode with the command CPACTIME.

Monitor Functions

The MFJ-1278B's protocol is designed for setting up "circuits" between two stations. However it can also operate in a mode more suitable for a "net" or "round-table" discussion with several participants, although reliable reception of all transmissions by every station cannot be guaranteed. This is done by enabling the monitor functions. Most of the monitor functions are described in Chapter 4.

Monitoring is enabled by the command MONITOR ON, and separate monitor functions are individually enabled.

If connected packet QSOs are taking place on the frequency of your group conversation, you may wish to ignore all connected packets while your group operates in unconnected mode. The command MALL OFF causes the MFJ-1278B to ignore connected packets.