7526 DCT Reference

File 9&mdash.Transaction Queue File

File 9 is a polled file (transaction queue) and is used by the 7526 DCT to store buffered transaction records. These records are retrieved in a first-in first-out sequence by polling from the terminal controller.

The maximum size of a transaction record is 255 bytes, which begins with a function ID header and includes the control characters STX, CS1, CS2, and ETX. Refer to Table 9. for more information on the function ID.

In the 7525 Compatibility mode, transaction records begin with a two-byte function ID.

The function ID bytes are decimal characters and start at 00. In Interactive mode, 50h is added to the function ID.
If error logging is defined in File 0 Record 00 Offset 7, a '4' will be placed in front of the two-byte function ID for invalid length reads, and a '9' will be put for invalid magnetic reads.

In the Enhanced mode, transaction records begin with a three-byte function ID.

The first byte contains the type of transaction
- Valid values for byte 1 are:
  - I = Interactive mode
  - B = Buffered mode
  - E = Error transaction-Interactive mode
  - F = Error transaction-Buffered mode
  - V = Request for remote validation
The next two bytes contain the function ID as an ASCII hex string.

Normally, the transaction data follows the ID as it was entered. The time stamp follows the data; a sequence number can follow the time stamp and the last entry of each transaction record is always a record separator. See offset 6 and 21 of Table 5.

Table 9. File 9 Function ID Comparison


+=====+==============+====+=========================+======+==================+
| Description             | 7525 Compatibility Mode | Enhanced Mode Function  |
|                         |       Function ID       |           ID            |
+=====+==============+====+=========================+======+==================+
| Programs 1-28 (F1-F28)  |        0-27 Dec         |        01-1C Hex        |
+-----+--------------+----+-------------------------+------+------------------+
| Badge Initiated Program |         30 Dec          |         1D Hex          |
+-----+--------------+----+-------------------------+------+------------------+
| Fast Clock Program      |         29 Dec          |         1E Hex          |
+-----+--------------+----+-------------------------+------+------------------+
| 31-42                   |    PF Key-Initiated     |           N/A           |
|                         |      Transactions       |                         |
|                         |  (Not accessible by a   |                         |
|                         |  physical key stroke)   |                         |
+-----+--------------+----+-------------------------+------+------------------+
| 43-54                   |       Shifted PF        |           N/A           |
|                         |      Key-Initiated      |                         |
|                         |      Transactions       |                         |
|                         |  (Not accessible by a   |                         |
|                         |  physical key stroke)   |                         |
+-----+--------------+----+-------------------------+------+------------------+
| 55-56                   |  RS-232 serial ports 1  |           N/A           |
|                         |     and 2-Initiated     |                         |
|                         | (initiated by incoming  |                         |
|                         | data on optional serial |                         |
|                         |         ports)          |                         |
+-----+--------------+----+-------------------------+------+------------------+
| DI Initiated            |           N/A           |        39-40 Hex        |
| Transactions            |                         |                         |
+-----+--------------+----+-------------------------+------+------------------+
| Date/Time               |         28 Dec          |         79 Hex          |
+-----+--------------+----+-------------------------+------+------------------+
| Command D               |        31/81 Dec        |         FC Hex          |
+-------------------------+-------------------------+-------------------------+
| Records 31-56 require sending :9  if DI/DO initiated transaction (records   |
| 57-64) are to be active.                                                    |
+-----------------------------------------------------------------------------+