Siemens SIMATIC S5-95U - Page 74

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
9600480024001200600300200
20305090170310510
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a 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 4-15