xmodem Command

Purpose

Transfers files with the xmodem protocol, detecting data transmission errors during asynchronous transmission.

Syntax

xmodem { -s | -r } FileName

Description

The xmodem shell command is used with the Asynchronous Terminal Emulation (ATE) program to transfer a file, designated by the FileName parameter, using the xmodem protocol.

The xmodem protocol is an 8-bit transfer protocol to detect data transmission errors and retransmit the data. The workstation sending data waits until the remote system sends a signal indicating it is ready to receive data.

After the receiving system get data, it returns an acknowledgment to the sending system. In the ATE program the receiving system times out if data is not received within 90 seconds after the file transfer is initiated.

Sending and receiving with the xmodem command are complementary operations. One system must be set to send while the other is set to receive. Use the xmodem command on the remote system in combination with the send subcommand or the receive subcommand from the ATE Connected Main Menu on the local system.

To interrupt an xmodem file transfer, press the Ctrl-X key sequence.

Note:

The DOS operating system terminates each line in an ASCII file with a newline character and a carriage return (Ctrl-M) character. UNIX terminates each line in an ASCII file only with a newline character. The carriage return characters are preserved when a DOS file is transferred to AIX®. The vi text editor can be used to remove spurious Ctrl-M characters using the subcommand
```
:%s/<Ctrl-V><Ctrl-M>//
```
where <Ctrl-V> and <Ctrl-M> each represent a single control character that is typed. However, since Ctrl-V is the default ATE MAINMENU_KEY, the ATE defaults must be altered in order to issue the vi subcommand while logged in via ATE.
The xmodem file transfer process adds Ctrl-Z characters to the last packet transferred to make the packet 128 bytes long. Most files transferred will, therefore, have Ctrl-Z characters appended to the end. The DOS operating system terminates an ASCII file with a Ctrl-Z character. Every file transferred from DOS to AIX will, therefore, end with at least one Ctrl-Z character. These extra Ctrl-Z characters can be removed with the vi text editor.

Flags

Item	Description
-r	Receives data from the local workstation.
-s	Sends data to the local workstation.

Examples

Sending a File with the xmodem Protocol

To send the file myfile with the xmodem protocol, use the ate command and the connect or directory subcommand to establish a connection to the remote system.

After logging in to the remote system and before pressing the MAINMENU_KEY (usually the Ctrl-Vkey sequence) to return to ATE on the local system, enter:
```
xmodem -r myfile
```
at the shell command line. The xmodem protocol starts receive mode on the remote system.
Press the MAINMENU_KEY to return to ATE on the local system.
The ATE Connected Main Menu displays.
Enter the send subcommand at the prompt on the ATE Connected Main Menu:
```
s myfile
```
The send subcommand instructs the local system to send myfile to the remote system. After transferring the file, the ATE Connected Main Menu displays.

Receiving a File with the xmodem Protocol

Receive the file infile from a remote system using xmodem protocol with the ate command and the connect or directory subcommand establishing a connection to the remote system.

After logging in to the remote system and before pressing the MAINMENU_KEY (usually the Ctrl-V key sequence) to return to ATE on the local system, enter:
```
xmodem -s infile
```
at the shell command line. The xmodem protocol starts, in send mode, on the remote system.
Press the MAINMENU_KEY to return to ATE on the local system.
The ATE Connected Main Menu displays.
Enter the receive subcommand at the prompt on the ATE Connected Main Menu:
```
r infile
```
The receive subcommand instructs the local system to receive infile from the remote system. After transferring the file, the ATE Connected Main Menu displays.

File

Item	Description
ate.def	Contains ATE default values.