Printronix P6000L, Руководство пользователя

Страница: 88 / 234

Vertical Format Units 5-4
End Load Code - 6F Hex
The DAVFU End Load code is 6F (hex), regardless of the state of the PI line. Before the End
Load code is received during the load routine, the state of the PI line is ignored. Sending the
End Load code terminates the DAVFU memory load routine.
Using The DAVFU
Once the DAVFU program has been loaded, it can be accessed by sending the appropriate
channel instruction to the printer. The paper is slewed to the physical line on the form having
the specified channel number assigned in the DAVFU memory. This is accomplished only with
the PI line held high. For a data byte to be recognized as a DAVFU channel instruction, the
following criteria must be met:
1) PI line must be high
2) Data bit 5 must be 0 (not set)
Given these two conditions, the lower 4 bits of a byte will specify the DAVFU channel number.
Table 5-3 lists DAVFU channels and their equivalent data bytes.
Clearing The DAVFU Memory
The following actions will reset (clear) the DAVFU memory.
1. Only Start Load and End Load codes are sent (no channel assignment data).
2. An odd number of DAVFU characters (channel assignment data) are sent and are deĆ
tected after the End Load code is received. Remember, two data bytes are required per
line.
3. A second Start Load code is received, resulting in reinitialization of the DAVFU memory
routine. This allows the routine to be restarted.