This appendix will teach you how to use AT commands to
configure the simulator for your test requirements
interrogate the simulator regarding its state
command the simulator to perform an action
query the simulator regarding AT command syntax
AT commands may be used to set the configuration of the MOB-IP-SIM, to query the simulator about its state, to command it to perform an action, or to test for the existence and syntax of a command. While the MIP-5850 is expected to be used by a mobile device software engineer who requires significant control of the PPP and Mobile-IP connection, the MIP-5800 user is expected to be the user applications programmer, who requires only those commands required to establish a normal Mobile IP connection for applications testing. The MIP-5800 command set is therefore smaller than that of the MIP-5850. With either model, the AT commands may be used over either the Ethernet or serial ports.
To configure the MOB-IP-SIM the appropriate command must be followed by one or more arguments. Some action commands may also require arguments. To query the simulator a command is followed by a question mark. To test a command requires following the command with =?. Some commands allow setting a value, or take an action that requires arguments. Use the command name followed by = and a value. Some of these commands return a value.
Action commands are used by themselves or sometimes with arguments:
Test commands are those followed by =?, which all commands support. The response is an indication of the syntax of the commands arguments. If no arguments are used, an empty template is returned.
Templates consist of the following pieces:
Decimal numbers and ranges in parentheses
(0-9) One of the integers 0 through 9 inclusive.
(0, 1-9) One of the integers 0 through 9 inclusive, but number 0 is special.
(0.0-9.9) Real numbers 0.0 through 9.9.
Character strings specified in hexadecimal
A string of printing ASCII characters and blanks
A string of lower case as and blanks
Hexadecimal numbers and ranges
Punctuation
Some commands allow querying the current value of some parameter by adding a ? to the name of the command. The response returns the current value.
In the description following, each command description lists the methods supported (except for the =? test).
After the controller issues a command, the MOB-IP-SIM returns one or more lines of response. Each line is terminated with carriage return and line feed.
Every command returns a basic result code, currently either OK or ERROR, as its last line of response. Some commands return extended response lines, which start with a plus sign followed by the command name, a colon, a blank, and some additional information. This additional information is the return value.
Many of the AT commands affect and read configuration data visible from the web pages, one command per datum. While changes to some of these data, such as the fields in Mobile IP messages take effect immediately, changes to others such as the IP address and PPP settings, do not.
The commands are discussed using the following format:
+command [argument]
Query, Immediate, Disruptive, and/or Action
The command description
The template entry indicates what at+foo=? returns, if anything.
A command is labeled Query if it supports the =? command.
A command is labeled Immediate if it has an immediate effect but does not disrupt operation any more than one would expect from changing that parameter.
A command is labeled Disruptive if it forces changes to take effect other than what one may expect from the name or one-line summary of the command.
A command is labeled Action if it has a no-argument form.
The commands listed under "General Commands" are available on both the MIP-5800 and MIP-5850 simulators. The remaining commands are available only on the MIP-5850.
The serial port operates at 9600 bps, with 8-bit characters, no parity, one stop bit. It has the usual IBM AT-style pinout, so you need a null-modem cable to connect it to a PC. Commands are terminated by a CR character (decimal 13); each response line is terminated by CRLF (decimal 13, 10).
The MOB-IP-SIM also listens on TCP port 53614. On this port, both command lines and response lines end in CRLF, in accordance with the usual Internet conventions. A normal TELNET client starts in a mode compatible with the MOB-IP-SIM command processor.