USWD500 User’s Manual Version 3.0
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Step 3
Define data formats for transaction.
The data formats include the output format of the card reader, authorization
request format, and authorization response format. You can enable data
encryption here by using the defined specific data format.
Step 4
Credit card verification process
When a customer pays with a credit card, the card reader reads the information
from the credit card and sends this data to the authorization server on the CDPD
network. If this transaction is confirmed by the credit card center, the USWD500
Modem receives a confirmation message at the local site and displays messages
identifying the transaction as valid.
Step 5
The application layer with a point-of-sale device
The following is a typical sequence of commands you would perform to complete
the initialization/power-up process and the authorization procedure.
Initialization is usually performed during power-up or is part of a function key
procedure. To begin the initialization procedure, raise RTS prior to sending these
commands in sequence. Remember to clear your device’s receive buffer just prior
to sending commands.
Pause for 1 second after sending the
&F
command. There is no need to interpret
responses to this command.
AT&F
Factory reset
The response to each of these commands should be
<STX>0<ETX>{lrc}
. Any
other response is an error condition. All responses will be framed in
<STX>response<ETX>{lrc}
format. A 5-second timeout for receiving the
response is a good guideline.
AT\N3
Set side preference to
A preferred
(3) (See Note 2.)
AT&W
Save to non-volatile memory
Pause for 2 seconds after sending the
ATZ
command. There is no need to
interpret the response to the
ATZ
command.
ATZ
Reset the device.
Before you begin the transaction procedure, you should continuously issue the
AT!D
command. When
AT!D
returns a status of
RNI
, you’re ready to begin the transaction
procedure.
