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Channel 1 - The
Channels 2 through 11, 13 and 14 - Used as general channel codes (line identification codes) or filler channels. Each line on the form must be identified by a channel code. When the operatF ing program sends the channel code, the paper advances to the line identified by the channel code. Lines not used by the operating program must be identified by filler channels (unused channel codes).
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 channel 12 is not loaded in the EVFU memory, a single line feed will be 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 chanF nels 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 lights. Sending the appropriate channel code to the printer will cause 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.
For a data byte to be recognized as an EVFU instruction, the following criteria must be met:
1.PI line must be enabled and set high; and
2.Data bit 5 must be 0 (not set).
OR:
1.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
Vertical Format Units |