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User’s Manual
Appendix 4
Supported AT Commands
When ESERV-10 is configured to operate on AT command mode, the following AT commands are
supported on the serial communication. These commands can be used to control the connection
establishment and the e-mail communication. At the end of this Appendix is a list of messages from
ESERV-10 to the user.
AT
AT is a test command that does nothing but returns “OK”
Example:
AT
↵
OK
ATD
ATD is a dial command. ESERV-10 tries to open a connection to the previously dialled IP address
and port by using UDP or TCP communication, depending on the definition in the internal settings
of ESERV-10. In case of none previous dialling, the ESERV-10 uses unit’s internal default client IP
address and port. For a successful data channel establishment ESERV returns “CONNECT” and
enters to the data communication state. Otherwise “NO CARRIER” is returned. When ESERV-10
leaves the communication state (either by socket timeout or close by client etc.) it returns “OK” and
goes back to the AT communication mode.
Example of a successful data channel establishment:
ATD
↵
CONNECT
ATDxxx.xxx.xxx.xxx
ATDxxx.xxx.xxx.xxx,pppp
ATDxxx.xxx.xxx.xxx/pppp
These are AT dial commands with a client information. ESERV-10 tries to open a connection to the
given IP address (xxx.xxx.xxx.xxx) and port (pppp). Without the port information, ESERV-10
specifies the previously dialled port or the default client port, depending on the definition in the
internal settings of the ESERV-10. Otherwise the functionality is same as for the ATD command
described above.
Example of an unsuccessful data channel establishment to the IP address 172.16.8.10 and port
1230:
ATD172.16.8.10,1230
↵
NO CARRIER
+++ (Switch from data state to AT mode)
When ESERV-10 is on the data communication state (for example after a successful ATD
connection establishment) it needs to be returned to the AT command state in order to accept AT
commands. This is carried out by keeping one second pause on the data transmission, typing three
‘+’ characters within one second and keeping an additional one second pause after the last ‘+’.
ESERV-10 responses with “OK” message when it leaves the data communication state. Note that
the connection is retained on the background but data cannot be transferred before the data state is
activated again.
Example:
(one second pause)
+++
(one second pause)
OK
ESERV-10
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