Siemens SIMATIC S5 Series, Manual

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S5-95U, Second Serial Interface ASCII Driver
Example of a character frame:
Figure 4-9 Example of an 11-Bit Character Frame
SA 0 1 2 3 4 5 6 7 PA SO
Start bit
Stop bit
Data bit No. Parity bit
Waiting times CR, LF, FF (WCR, WLF, WFF)
The DB1 parameter
”
WCR
”
specifies the waiting times for the transition to the next line for a
printer.
The DB1 parameter
”
WLF
”
specifies the waiting time for feeding the paper of a printer to the
beginning of the next print line.
The setting of the DB1 parameter
”
SLF
”
can be selected in such a way that the printer paper is
not fed up to the beginning of the next print line.
The DB1 parameter
”
WFF
”
specifies the waiting period for the page feed for a particular printer.
Character delay time (DT)
It is the maximum time interval between receiving of two characters (character delay time). Only
those characters are recognized as valid and transmitted as a frame to the CPU whose delay is
shorter than the defined time.
In DB1.
”
DT 100
”
is preset, i.e. the character delay time is 100 ms.
Table 4-7 Character Delay Time for ASCII Driver Depending on the Transmission Rate
Transmission Rate in
bit/s
Min. Adjustable Charac-
ter Delay Time in ms
9600 4800 2400 1200 600 300 200
20 30 50 90 170 310 510
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
If you have set a smaller value in DB1 than the one specified in Table 4-7, the ASCII driver
automatically sets the minimum adjustable character delay time.
Frame length (ML)
The DB1 parameter
”
ML
”
(frame length) is relevant for the non-interpretive mode (mode No. 1, 2,
3) of the ASCII driver when receiving data frames.
In the interpreting mode, the receive frames must have a fixed length. In DB1,
”
ML 64
”
is preset,
i.e. frames of a maximum length of 64 bytes can be received.
Please ensure that the same frame length is parameterized in the S5-95U and in the communication
partner.
EWA 4NEB 812 6095-02
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