
Manual VIPA System 300S SPEED7
Chapter 5 Communication protocols
HB140E - CP - RE_341-2CH71 - Rev. 09/46
5-3
ASCII
ASCII data communication is one of the simple forms of data exchange
that may be compared to a multicast/broadcast function.
Individual messages are separated by means of character delay time
(ZVZ). Within this time the transmitter must have sent its telegram to the
receiver. A telegram is only passed on to the CPU if this was received
completely.
The receiving station must acknowledge the receipt of the message within
the "time delay after command" (ZNA) or command window that was
defined in the sending station.
These time stamps may be used to establish a simple serial communi-
cation link.
Since during ASCII transmission apart from the usage of the parity bit no
further step takes place for data protection, the data transfer is very
efficiently however not secured. With the parity the inversion of one bit
within a character may be secured. If two or more bits of a character are
inverted, this error may no longer be detected.
For the deployment of the ASCII protocol you have to add to your master
system a SPEED-Bus slave and to configure a CP 341-2CH71(ASCII) as
described at "Hardware configuration".
The properties dialog of the CP may be opened by a double-click. Every
parameter of the ASCII protocol may be accessed via the register
Parameter Assignment
with
Device-specific parameters
.
Related to the interface the interface number COM1 respectively COM2 is
put in front of the parameter designation.
Here the transfer speed in bit/s may be selected from a selection list.
Range of values: 150 ... 115200
Default: 9600
Leave this value preset to "ASCII". If "No protocol" is set, the interface is
deactivated and on a send job you will get an according error message.
Range of values: No protocol, ASCII
Default: ASCII
Number of bits onto which a character is mapped.
Range of values: 5 ... 8
Default: 8
Mode of operation
Proceeding
ASCII parameters
Transmission rate
Protocol
Data bits
Summary of Contents for CP 341S
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Page 4: ...Contents Manual VIPA System 300S SPEED7 ii HB140E CP RE_341 2CH71 Rev 09 46 ...
Page 8: ...Safety information Manual VIPA System 300S SPEED7 4 HB140E CP RE_341 2CH71 Rev 09 46 ...
Page 70: ...Index Manual VIPA System 300S SPEED7 A 2 HB140E CP RE_341 2CH71 Rev 09 46 M Stich ...