Printronix P9000 Series - Manual (Page 94)

Vertical Format Units 5-14
A maximum of 12 channels can be assigned to one physical line on the form. Two eight-bit data
bytes (CVFU characters) are required per line. As shown in Table 5-10, the least significant 6
bits of the first data byte are used to assign channels 1 through 6; the least significant 6 bits of
the second data byte are used to assign channels 7 through 12. If a bit is set, the corresponding
channel is assigned.
Each line on the form requires two bytes. For lines not requiring a channel identification, the
two bytes should not contain channel assignments.
This procedure can be continued for a maximum of 126 lines (252 CVFU bytes). The CVFU
memory is cleared if more than 252 bytes are received before the end load code.
CH 1 TOF - The first channel, line 1 of the form, must be assigned channel 1, top-of-form
and Channel 2 must not be defined in this first byte (byte one, bit 2 must be 0) or the entire load
sequence is ignored and the memory reset. After the memory is loaded, a Form Feed code (FF,
0C hex) will move the paper tothe next channel 1 (top-of-form).
After the channel assignment on the last line of the form, another channel assignment code
must be sent with the top-of-form bit set (called the dummy TOF"). This channel assignĆ
ment code does not count as a line of the form. All data received after the dummy TOF will be
ignored until the end load code is received. Data received after the the dummy TOF is counted
as part of the maximum allowed (126 lines, 252 bytes).
CH 2 VT - Channel 2 is used as the vertical tab channel. After the memory is loaded, a VT code
(0B hex) will move the paper to the next channel 2. If a VT code is received but channel 2 is not
loaded, the paper will advance to the next TOF position. If a VT code is received but the CVFU
is not selected or not loaded, a s8
ingle line feed occurs.
End Load Code - 1E Hex
The CVFU end load code is 1E hex. This terminates the CVFU memory load routine.
Table 5-10. CVFU Channel Assignment
Channel # Bit #
6
5
4
3
2 - VT
1 - TOF
6
5
4
3
Channel #
2
1 (LSB)
12
11
10
9
8
7
8
7 X (don't care)
SECOND DATA BYTE FIRST DATA BYTE
Bit #
8
7
6
5
4
3
2
1 (LSB)
X (don't care)
set high (1) set high (1)
Value
Binary
128
64
32
16
8
4
2
1
Value
Binary
128
64
32
16
8
4
2
1