Siemens SIMATIC S5 Series Manual page 69

ASCII Driver
ASCII mode number (MOD)
You can define the type of data traffic by means of the mode number (1 ... 8).
Two protocol types can be distinguished:
• Non-interpreting mode (mode no. 1, 2, 3)
Data is exchanged without XON/XOFF protocol.
• Interpreting mode (mode no. 4 ...8)
Data is exchanged with XON/XOFF protocol. When the signal state of the bit "receiving
allowed" changes, the ASCII driver sends:
- XOFF at the falling edge or
- XON at the rising edge.
Table 4-3 shows the meanings of the individual mode numbers. The definitions of the DB1
parameters "ML" or "ME" in Table 4-3 serve as an example. All parameters of the permissible
range of values are valid ( Table 4-2).
Mode
Transmitting n bytes; n
mailbox.
1
Receiving m bytes; m
Transmitting or receiving data until the end-of-text character defined in
2 the parameter set (low-order byte) is sent or received. The end-of-text
character is transferred.
Transmitting or receiving data until the two end-of-text characters
defined in the parameter set are sent or received. The two end-of-text
3 characters are transferred.
End of text is only recognized if the character defined in the high-order
byte is sent or received prior to the character defined in the low-order
byte.
As mode 2 but ASCII characters are interpreted when received:
RUB OUT : Delete last character
4 XON
XOFF
As mode 3 but ASCII characters are interpreted when received:
RUB OUT : Delete last character
5 XON
XOFF
* n is variable when sending
** m is fixed in the case of the receiver
4-10
Table 4-3 Meaning of the Mode Number
Meaning
must be specified in the first word of the send
*
is specified in the ASCII parameter set.
**
: Continue to send
: Abort transmission and wait for XON
: Continue to send
: Abort transmission and wait for XON
S5-95U, Second Serial Interface
Definition of
the ML/ME
Parameters
ML 64
ME 0 13
ME 13 10
ME 0 13
ME 13 10
EWA 4NEB 812 6095-02