Printronix P6000L, Руководство пользователя

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5-11 Vertical Format Units
Figure 5-2. Sample P-Series EVFU Form Definition Program
The format for the form definition program sent from the host computer is as follows.
1. EVFU Start Load code.
2. The channel 2 code is sent two times to define the first two lines of the form as fillers. AlĆ
ternatively, the channel 1 code, top-of-form, could have been the first code sent to deĆ
fine the first line of the form as the top-of-form position.
3. The channel 1 code is sent to assign the top-of-form position to the first line printed on
the form, rather than using the top-of-form code to define the first line on the form.
4. A series of channel codes are sent, one for each line of the form. If the form is 25 lines long,
25 channel codes must be sent. Each line to be accessed for printing by the operating proĆ
gram should have a unique channel code. Lines not to be accessed for printing by the operĆ
ating program should have a filler channel code assigned. One filler channel code can be
used for all blank" lines of the form.
5. EVFU End Load code.
The top-of-form code can be used to identify the first line of the form, whether or not it is the
first line printed, or it can be used to identify the first line printed. In this example, the top-
of-form code, channel 1, is used as the line identification code of the first line to be printed,
not the first line of the form. In the case shown by the example, a Form Feed code, pushing the
TOF switch on the control panel, or sending the channel 1 code will slew paper to line 3 of the
form.
To avoid confusion, it is best to assign unique channel numbers to each line printed. If you have
an exceptionally long form with a large amount of lines, one channel code can define more than
one line. In Figure 5-1 for example, both line 5 and line 8 of the form could have been assigned
channel 4. When the host computer sends the channel 4 code the first time, the EVFU slews the
paper to line 5 and prints the AGE data. When the host computer sends channel 4 the second
time, the EVFU slews the paper to line 8 and prints the DEPARTMENT data. (If a third line
was defined by channel code 4, that line would be accessed by the next occurrence of channel
code 4 in the data stream, etc. Otherwise, the next occurrence of channel code 4 in the data
stream would cause the EVFU to slew paper to the first line identified by channel 4 on the next
form.) This procedure allows a single channel code to define more than one line on the form,
but you must be aware of which line of the form is being accessed by the number of occurrences
of the channel code in the data stream.
In the example shown in Figure 5-2, channel 2 is used repeatedly as the filler channel. The
print program would not send the channel 2 code. The lines identified by channel 2 are always
blank.
Table 5-7 defines the functions of the EVFU channels used in the Figure 5-2 example.