M-S Cash Drawer A794 - Manual (Page 49)

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.