Cinterion
®
ENS22-E AT Command Set
7.8 AT^SISR
ENS22-E_ATC_V01.000
19/02/11
Page 113 of 189
Notes
• The URC "
: x, 1" notifies that a package data is available for reading, if this package data is not read
out, the notification of the next package data will not be displayed. 4096 bytes data can be cached at most, If
the newly received data is larger than the remaining capacity, it will be discarded.
•
Cinterion
®
ENS22-E can't handle packet after IP fragment. For this reason, the data sent to
Cinterion
®
ENS22-E needs to be less
than the Path MTU.
7.8.1
Example: Socket Host Reads Small Amounts of UDP Data Pack-
ets (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 is available for reading.
at^sisr=0,6
The host requests to read 6 bytes.
^SISR: 0, 6, 12
THIS_I
The first 6 bytes of datagram A are confirmed and transmitted. Another
12 bytes are still available.
OK
at^sisr=0,6
The host requests to read the next part of 6 bytes.
^SISR: 0, 6, 6
S_DATA
The next 6 bytes of datagram A are confirmed and transmitted. Another
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
GRAM_A
Last part of datagram A was received, no remainder is left.
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
^SISR: 0, 3
NEW
3 bytes are confirmed and transmitted. Datagram B was properly
received.
OK
