Response Codes; Outgoing Calls - Equinox Systems ESP-2 MI Installation And User Manual

When a port enters command mode, the remote ESP-2 hub will not be aware of this
state change. The remote hub will obviously not be receiving any data from the TCP
connection, but if it receives serial data from its attached device, it will attempt to
send it to the ESP-2 hub that is not listening because it is in command mode. In this
case, the data will be buffered until the port on the intended recipient ESP-2 hub
returns to data mode.

Response codes

The ESP-2 hub will respond to an AT command from the serial device with OK or
ERROR plus the status of the TCP connection to the remote endpoint.
Table 12 lists the possible response values, that is, when response codes are enabled
and the applicable format (numeric or text) is enabled.
Table 12: Modem Command Response Codes
Numeric Codes (ATV1 or ATV2)
0
2
3
4
5
6
7
8

Outgoing calls

When the Allow Outgoing Calls option is enabled and the ESP-2 hub is idle, input
will be parsed for valid ATDT strings and a TCP connection will be attempted to the
remote end. If another call is active, any connection request will be ignored, even if
the Escape to Command Mode string (+++) is detected.
If the Monitor DCD option is enabled, the connection will be rejected if the control
signal is logically low. The connection will be closed if the inbound control signal
transitions from logically high to low during the call.
In all cases, when a TCP connection is active, the ESP-2 hub will raise the outbound
DTR signal to indicate that the connection is valid (which should be seen as inbound
DCD by the serial device, which is usually a PC when modem emulation is used). If
the TCP connection drops, DTR will be lowered to indicate a Carrier Drop to the
attached serial device.
Equinox ESP-2 MI Serial Hub Installation and User Guide
Text Code (ATV0 or ATV3)
OK
Ring
No Carrier
Error
Connect
No Dialtone
Busy
No Answer
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