AC75 AT Command Set
s
AC75_ATC_V01.002 Page 254 of 569 10/30/06
Confidential / Released
need to do so several times until the service confirms that data can be sent or received.
• The first parameter of the AT^SISR or AT^SISW commands is always the <srvProfileId>, the second
parameter is the number of bytes which the host either wants to send to or is able to receive from the module.
The way the module handles the data transfer follows the rules of the ordinary socket interface and is aware
that a host may be limited by its input buffer size. The maximum data size supported by AC75 is 1500 bytes
in both directions (read or write). To send or receive more than 1500 bytes, the read or write action shall be
repeated until the data transfer has completed. Each read or write action requires that the command response
(of AT^SISR or AT^SISW) confirms that the service is ready to send or receive data.
To end an upload data stream set the <eodFlag> in the last AT^SISW command.
•The AT^SISI command shall be used to monitor the progress of the session. The command reports the ser-
vice state of the used service profile and indicates the number of bytes received, the number of bytes sent
and, in the case of sending, the number of bytes acknowledged or unacknowledged at TCP layer.
• If an error occurs durin g a session you can enter the AT^SISE command and the <srvProfileId> to iden-
tify the reason. This is especially important in polling mode.
• Finally, to end a session, enter the AT^SISC write command and the <srvProfileId>.
Additional AT commands designed for controlling and monitoring the connection profiles (bearers):
•The AT^SICI command can be used any time to query the current status of one or all connection profile(s).
•The AT^SICO command opens a connection and keeps it open until closed with AT^SICC or disconnected
by the network.
•The AT^SICC command closes a connection set up with AT^SICO.
•The AT^SISX command sends ICMP (Interntet Control Message Protocol) Echo Requests to a target IP
address or host name to verify the TCP/IP network connection.
Maximum number of profiles defined / used:
• Up to 6 connection profiles can be created (with AT^SICS).
• Up to 10 service profiles can be created (with AT^SISS), but the number of parallel profiles of the same ser-
vice type is limited as listed below. If the maximum number of a service profile type is already defined, any
attempt to set up another profile for the same type will be denied with "+CME ERROR: operation of service
temporary not allowed".
- Maximum 3 HTTP profiles
- Maximum 6 socket profiles: Only 2 instances can be opened for listener, meaning that if 2 listeners are
established another 4 instances can be opened for clients. Also, the socket service can accept an incom-
ing connection only when at least one service profile is still free (not yet created with AT^SISS), otherwise
the incoming connection will be rejected from the listener. If there is no listener established all 6 socket
profiles can be configured as client.
- 1 FTP profile
- 1 POP3profile
- 1 SMTP profile
• The TCP/IP stack of AC75 supports using several service profiles at the same time, provided all of them are
running on the same connection profile (bearer). For example, it is possible to download files from an FTP
server, while sending and receiving emails at the same time.
Using Internet Service AT commands on several interfaces (ASC0, ASC1, USBor Multiplex mode on ASC0):
• A connection profile can be created on one interface and then viewed or changed on all other interfaces.
• A service profile can be used only on one interface at a time:
- Service profiles can only be opened on the interface where they have been defined with AT^SISS.
- Accordingly, on each interface the read commands AT^SISO? and AT^SISI? deliver full status informa-
tion for the service profiles configured / opened on this interface, while service profiles related to other
interfaces are only listed by <srvProfileId> and service type name (= <srvParmTag> value "srv-
Type") without any status parameters.
- Changes to a service profile are allowed only on the same interface where it was created, trying to change