Siemens SIMATIC S5 CP 523 Manual page 19

CP 523
2.3 Serial Interface CP - Peripheral Device
The CP 523 is equipped with an RS-232-C (V.24) interface and a TTY interface. You can set the serial
interface parameters in two ways:
• In the user program with job number 90
( 7.3.2).
The CP 523 copies the parameter setting data from the submodule into a RAM area on the CP
during startup. If the CPU transfers new parameter setting data to the CP during operation,
the CP continues with the new data.
• In data block 1, parameter block 0, on the user submodule (Print mode
Communications mode 7.3.1).
Data is transferred between the CP and the peripheral device in a 10-bit or 11-bit character frame.
Three data formats are available for each character frame.
10-Bit-character frame
• 1 start bit, 7 data bits, 2 stop bits
• 1 start bit, 7 data bits, 1 parity bit, 1 stop bit
• 1 start bit, 8 data bits, 1 stop bit
11-Bit-character frame
• 1 start bit, 7 data bits, 1 parity bit, 2 stop bits
• 1 start bit, 8 data bits, 1 parity bit, 1 stop bit
• 1 start bit, 8 data bits, 2 stop bits
1st example:
Character frame: 10-bit
Data format: 7 data bits (1 start bit, 7 data bits, 1 parity bit, 1 stop bit)
.:
Bit no
1
0
1 start
bit
Figure 2-3. 10-Bit Character Frame with 7 Data Bits, 1 Parity Bit and 1 Stop Bit
EWA 4NEB 811 6044-02a
2 3 4 5
7 data bits
"Set interface parameters" parameter block
H
(data format 3 in parameter block 0)
(data format 4 in parameter block 0)
(data format 5 in parameter block 0)
(data format 0 in parameter block 0)
(data format 1 in parameter block 0)
(data format 2 in parameter block 0)
6 7 8 9
1
0
1 pari-
ty bit
Technical Description
10
1
1 stop
bit
6.3.1,
2-5