Telpar MTP-1500, Руководство пользователя

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handshaking if selected. Dip Switch
SW2 position 7 ON reconnects this
signal to be a hardware RESET input
signal (normal connection to the DTR
line from a computer will hold the printer
always reset).
7 RTS O Same as DTR.
Table 23 - Serial (RS232C) Interface Pin Assignments
4.5.3 Flow Control
MEMORY switch 1 position 3 ON sets the BUSY condition when the receive buffer is full. OFF sets the BUSY
condition when the receive buffer is full or when Off Line.
The MTP-1500 employs a 4 K byte data buffer to allow the host computer to rapidly transfer data. Under some
circumstances it may be possible to completely fill the buffer . When the Receive Buffer is within 128 bytes of being
full, the MTP-1500 signals the host computer to pause until the receive buffer has room 256 bytes. The flow control
information is sent to the host using hardware or software protocols as determined by the DIP switch settings.
The hardware protocol uses the DTR line of the serial interface. This pin are asserted or negated as necessary to turn
off and turn on the flow of data. The software protocol uses the XON (11hex) and XOFF (13hex) ASCII control codes
which are sent back to the host to start and stop the data stream. When XON/XOF handshaking is enabled, the XON
and XOF are transmitted without checking the state of the DSR line of the I/O connector. Some host systems may not
support one or both of these protocols.
If memory switch 1 position 3 is set to OFF and DTR handshaking is enabled, then the DTR line goes to the BUSY
state whenever the printer is OFF LINE (see section 1.1.3 add bookmark) or when the receive buffer is full. If memory
switch 1 position 3 is set to ON and DTR handshaking is enabled, then the DTR line goes to the BUSY state from the
time power is turned on until the printer is ready to receive data, during self test, or when the receive buffer is full. If
XON/XOF is enabled then the DTR line goes to the BUSY state from the time power is turned on until the printer is
ready to receive data or during self test.
If XON/XOF handshaking is enabled the printer sends XON when the printer goes On Line after a power on,
when the receive buffer becomes available following a buffer full condition, when the printer switches from Off Line to
On Line, or when the printer recovers from an error using DLE ENQ 1 or DLE ENQ 2. The printer sends XOF when the
receive buffer becomes full or when the printerr switches from On Line to Off Line.
4.6 Centronics Parallel (IEEE-1284) Interface
4.6.1 Parallel I/O Connector
DB 25S, PC Pinout
Figure 13 - Parallel I/O Con++ Change dwg to CENT
??? add definition of 1284 handshaking protocol
Parallel Interface Pin Assignments
Pin Name Nibble & Byte
mode Direction Function
1 /STB HostClk I Active Low Pulse to send data tp
printer
2 DO DO I/O ASCII data bit 0 (LCB)
3 D1 D1 I/O ASCII data bit 1
4 D2 D2 I/O ASCII data bit 2
5 D3 D3 I/O ASCII data bit 3
6 D4 D4 I/O ASCII data bit 4