Specifications

Chapter 10 – Internet Service Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 166
Further write attempts with AT^SISR are denied as long as the <remainUdpPacketLength> is unequal 0 or is not
omitted. In this case the service returns "+CME ERROR: operation of service temporary not allowed".
0 Indicates that all bytes of the current UDP datagram are read.
1...(max. data size)-1 Indicates that the currently read UDP datagram is not yet complete. The displayed value
is the remaining number of bytes.
<remainUdpPacketLength> is unequal 0 until reading all parts of the current datagram
is finished.
<optServParm>
Service specific parameter of the AT^SISR write command response. If the Socket service is configured as UDP
endpoint this parameter returns the IP address and the UDP port of the remote host that has sent the current
UDP data.
Notes:
• Usage of the PIN is dependent on conditions specified for the command. Not all command types are PIN
protected (for example a write command can be PIN protected while the read command is not). Note: The
table provided in Section 19.3, Available AT Commands and Dependency on SIM PIN uses the same symbols.
• This command is not supported in airplane mode.
10.7.1 Example: Socket Host Reads Small Amounts of UDP Data Packets (URC Mode)
This section applies only to the Socket service using the UDP protocol. The example shows how to read UDP
packets if the buffer of the host application can handle only a few bytes. There are two datagrams available for
reading.
Buffer size: 6 bytes
Datagram A = 18 bytes (content "THIS_IS_DATAGRAM_A")
Datagram B = 3 bytes (content "NEW")
^SISR: 0,1 Service profile 0 is configured for Socket service and UDP. The URC notifies
host that data are available for reading.
at^sisr=0,6 The host requests to read 6 bytes.
^SISR: 0,6,12 The first 6 bytes of datagram A are confirmed and transmitted. Another 12 bytes
are still
THIS_I available.
OK
at^sisr=0,6 The host requests to read the next part of 6 bytes.
^SISR: 0,6,6 The next 6 bytes of datagram A are confirmed and transmitted. Another
S_DATA 6 bytes are still available.
OK
at^sisr=0,6 The host requests to read the next part of 6 bytes.
^SISR: 0,6,0 Last part of datagram A was received, no remainder is left.
GRAM_A
OK
at^sisr=0,6 Again, the host requests to read 6 bytes. This time, the request refers to
datagram B which has only 3 bytes. As the read datagram is smaller than the
size requested by the host, the response does not include the
<remainUdpPacketLength>.
^SISR: 0,3 3 bytes are confirmed and transmitted. Datagram B was properly received.
NEW
OK