MagTek IntelliStripe65 99875161 - Manual (Page 8)

IntelliStripe 65 Command Reference
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Message Type
This field specifies the message type: request, response or notification. The table below defines
the encoding of the message type:
Bits Value Definition
7-6 00 Request message type.
01 Response message type.
10 Notification message type.
11 Reserved for future use.
5-4 0 Reserved for future use.
3 0-1 Encryption flag. Zero when data field is not
encrypted. One when data field is encrypted.
When encrypted, the data field must be padded at
the end so that its length is a multiple of 8 bytes.
2-0 0-7 Pad length. The number of pad bytes at the end of
the data field when the data field is encrypted. If the
data field is not encrypted, the pad length is zero.
Requests are the messages sent by a host application to a device application. The device
performs the requested operation and sends a response message to the host application. The
device can service only one request at a time. If a request is pending, no further requests should
be sent to the device until a response is received.
Responses are the messages sent as a reply to a previously sent request. The response contains
the result of the requested operation. The device application must send each response within a
pre-determined finite amount of time from receiving the request.
Notifications are sent by a device application when it needs to notify the host application that the
device’s state has changed or that some external event has occurred (i.e., a magnetic card has
been inserted). The device can send a notification at any time. The device does not expect a
response or any specific action from the host application.
For device operations that take long or indefinite amount of time, the host application usually
sends a request that initiates the operation. The device sends a response, indicating it has started
the operation. When the operation completes, the device sends a notification message to the host
application.
Application ID
This field specifies the application ID. The application ID identifies the device application that a
message corresponds to. A device application is a functional subsystem in the device. For
example, a device might contain a magnetic stripe, transport, and a smart card functional
subsystem. Each application in a device has a unique application ID and a defined command set.