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Using the CVFU - 1F Hex
The VFU LOADED indicator on the control panel lights when the CVFU program has been enabled and loaded. Sending an 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 CVFU memory. For a data byte to be recognized as a CVFU channel inF struction, the following criteria must be met:
1.A 1F hex code must have been received; and
2.Data bit 5 must be 0 (not set).
Given these conditions, the lower 4 bits of a byte will specify the CVFU channel number. Table
Table
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| Data Bits |
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| CVFU Channel | ||
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Hex | Dec | Code | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 |
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1F | 31 | US | X | X | X | 1 | 1 | 1 | 1 | 1 | Start Execute | |
01 | 1 | SOH | X | X | X | 0 | 0 | 0 | 0 | 1 | 1 |
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02 | 2 | STX | X | X | X | 0 | 0 | 0 | 1 | 0 | 2 |
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03 | 3 | ETX | X | X | X | 0 | 0 | 0 | 1 | 1 | 3 |
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04 | 4 | EOT | X | X | X | 0 | 0 | 1 | 0 | 0 | 4 |
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05 | 5 | ENQ | X | X | X | 0 | 0 | 1 | 0 | 1 | 5 |
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06 | 6 | ACK | X | X | X | 0 | 0 | 1 | 1 | 0 | 6 |
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07 | 7 | BEL | X | X | X | 0 | 0 | 1 | 1 | 1 | 7 |
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08 | 8 | BS | X | X | X 0 1 0 0 0 | 8 |
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09 | 9 | HT | X | X | X 0 1 0 0 1 | 9 |
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0A | 10 | LF | X | X | X | 0 | 1 | 0 | 1 | 0 | 10 |
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0B | 11 | VT | X | X | X | 0 | 1 | 0 | 1 | 1 | 11 |
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0C | 12 | FF | X | X | X | 0 | 1 | 1 | 0 | 0 | 12 |
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X = Undefined, 0 or 1 |
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| 1 = High |
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| 0 | = Low |
Clearing the CVFU Memory
The following actions will reset (clear) the CVFU memory.
1.Only the start load and end load codes are sent (no channel data).
2.An odd number of CVFU characters (channel assignment data) are sent (detected after the end load code is received). Remember, two data bytes are required per line.
3.More than 126 lines (252 bytes) are sent without specifying the dummy TOF.
4.The first byte sent after the start load does not specify TOF or channel 2 is specified in the first byte.
Vertical Format Units |