Northern UTA220/UTA220k manual Initiate Software Download $Y=x, Softload

Softload

Initiate Software Download: $Y=x

The $Y command initiates a softload into the alternate software set. This command requires the softload password previously set by the %P1 command. If the password does not match the unit’s stored password, the TA will return an ERROR message.

If the password matches, the TA begins by displaying the softload method ID. This ID code must match the softload method ID of the new software to be loaded.

After displaying the method ID, the TA begins erasing the Flash memory devices for the alternate software set. If the erasure is successful, the TA returns a READY message and enters the YModem-G receive mode.

At this point, the TA is ready to accept a softload using the YModem-G file transfer protocol. The TA sends the YModem-G initiation character (G) until the DTE begins sending YModem-G frames. If no frames are received within two minutes, the TA will time out, send an ERROR message, and return to the AT command mode.

The YModem-G transfer should send one file. During the transfer, the TA may issue flow control requests to pace the DTE’s sending of data.

After the file has been transferred, the TA verifies that the file has been received and programmed correctly. The TA then sends a response code (OK or ERROR) to the DTE indicating the success or failure of the entire softload.

If an error occurs during the transfer, or if the host fails to respond to the YModem-G initiation requests, the TA returns with an ERROR message. In this case, the alternate software is marked as INVALID to prevent a swap attempt.

If an error occurs during the softload, the TA attempts to cancel the YModem-G transfer by sending a series of ASCII CAN characters (18 hex). It then returns to the AT command mode, echoing any characters received from the DTE. Depending upon when the host recognizes the cancel sequence, the host may begin to display the echoed softload characters on its screen. The DTE may also abort the transfer by sending 2 or more CAN characters between YModem-G frames.

An example of a typical softload session is provided at the end of this chapter.

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