M-S Cash Drawer A794 用户手册

下载
页码 147
Chapter 5: Communication Interface
A794 Owner’s Guide
December 1999
44
The next table shows that with no delay between lines, the transmit time is much less
than the process time, allowing the printer to print at full speed.
No Delay Between Lines
Char. per
Line
Lines per
Receipt
Transmit Time
(9600 Baud)
in Seconds
Transmit Time
(19.2 K Baud)
in Seconds
Transmit Time
(115.2 K Baud)
in Seconds
Process Time
in Seconds
20
20
0.40
0.20
0.035
0.50
20
40
0.80
0.40
0.070
1.00
44
20
0.88
0.44
0.075
0.50
44
40
1.76
0.88
0.150
1.00
XON/XOFF Protocol
The XON/XOFF characters coordinate the information transfer between the printer and
the host computer. The printer sends an XON character when it is ready to receive data
and it sends an XOFF character when it cannot accept any more data. The software on
the host computer must monitor the communication link as shown in the following
flowchart in order to send data at the appropriate times.
If XON/XOFF has been selected, the printer also toggles the DTR signal, as described in
the next section, but it does not look at the DSR signal to transmit data.
XON character = hexadecimal 11.
XOFF character = hexadecimal 13.