Printronix P3000 Series - Manual (Page 77)

5–3 Vertical Format Units
Channel 12 – Reserved as the Vertical Tab channel. The Vertical Tab code (VT, 0B hex) prints any data
in the print buffer and rapidly slews the paper to the next line identified by the channel 12 code. If chan-
nel 12 is not loaded in the EVFU memory, a single line feed is executed when a VT code is sent.
Channel 15 and 16 – Used as general channel codes or filler channels only when the VFU is accessed
by the PI line. In an EVFU form that does not use the PI line, the codes for Channels 15 and 16 function
as the Start Load and End Load codes.
End Load – 1F or 6F Hex
The end load code terminates the memory load program. The end load code is 1F hex when the PI line
is disabled (low) or 6F hex when the PI line is high. Channel codes in excess of 192 channels received
prior to the end load code are discarded.
Using the EVFU
Once the EVFU program has been enabled and loaded, the VFU LOADED indicator on the control
panel glows. Sending the appropriate channel code to the printer causes any data in the buffer to print
and slew the paper to the next line on the form having the specified channel number assigned in EVFU
memory.
To recognize a data byte as an EVFU instruction, the following criteria must be met:
1. The PI line must be enabled and set high; and
2. Data bit 5 must be 0 (not set).
OR:
1. The PI line must be disabled or low; and
2. Data bit 5 must be 1 (set).
Given these conditions, the lower four bits of a byte will specify the EVFU channel number. Table 5–1
lists the EVFU channels and their equivalent data bytes with the PI line enabled; Table 5–2 lists the
EVFU channel and their equivalent data bytes with the PI line disabled.