Siemens SIMATIC S5 CP 523 Manual page 121

CP 523
Hardware handshake (HW handshake)
This parameter is only significant for the RS-232-C (V.24) interface.
If you set HW handshaking ON, the "RTS", "CTS", "DTR" and "DSR" control signals of the RS-232-C
(V.24) interface are evaluated. The XON/XOFF protocol is not possible.
The default is HW handshake OFF, i.e. the control signals are not evaluated.
The HW handshake signals are neither evaluated nor affected in 3964(R) mode.
Parameter for XON/XOFF character
If you use the XON/XOFF protocol, you have a free choice of the XON/XOFF character. ASCII code
provides the codes 11
not use the same values for the XON and XOFF characters.
Data transfer is executed with the XON/XOFF protocol when valid values are used for XON and
XOFF.
XON/XOFF is not possible in Transparent mode (mode 1) or 3964(R) mode (mode 3).
Reader's note: Section 7.3.1 is arranged so that the parameter list (Table 7-2) and the parameter
descriptions which follow it are succeeded by the subsections
• Initializing TRANSPARENT MODE (page 7-16)
• Initializing INTERPRETIVE MODE (page 7-18)
• Initializing 3964(R) mode (page 7-21)
When you have chosen the mode you want to use, you can limit your reading to the appropriate
subsection.
The description of parameter block 9 applies for all modes, and was therefore presented only once
on page 7-42.
EWA 4NEB 811 6044-02a
(DC1) for the XON character and 13
H
Communications Mode
(DC3) for the XOFF character. You may
H
7-15