Epson ESC/VP21 User Manual page 38

and then waits indefinitely for an incoming valid 'AT' command string from
the DTE.
If the next character received by the modem is not an 'A' or 'a', then the modem
returns to data mode and sends a 'CONNECT message back to the DTE.
If the modem receives an 'A' or 'a', the modem disables the EPD timer (if it
has not time out) and sends the character to the remote modem. The mo-
dem then stores any received data from the DTE into the modem internal
command buffer and sends the data to the remote modem. Upon detecting
a <CR> or
receiving Up to
if a valid 'AT' command has been received and then processes the valid
commands. If a non-'AT' command string or an invalid command string has
been received then the modem will remain in data mode. If a valid 'AT'
command has been received, then the modem changes to command mode
and sends an 'OK message. After sending the 'OK message, the modem
will echo back any received data from the DTE while in command mode.
While in TIES command mode, the modem ignores certain characters that
may cause the modem to incorrectly decide that an incoming 'AT' string is
invalid. The ignore character are <LF>, <space>, and <CR> (<CR> is ig-
nored only when S3 is not equal to <CR>). Not all 'AT' commands are sup-
ported during TIES command mode. The following is a list of supported
commands:
E, H, M, O, Q, S, V, X, Z, and ampersand'&' commands
The escape character is determined by the value stored in S-register S2,
and is typically a + character. An example of the TIES Escape Sequence is
30
39 data characters, the modem then determines
COMMAND REFERENCE - 2