Siemens SIMATIC S5-100U System Manual page 477

S5-100U
The CP 521 SI (Serial Interface) communications module is a powerful I/O module with its own
central processor.
A separate manual is available for this module. It can be ordered under the order number 6ES5 998-
1UD21.
The following is an overview of the module's mode of operation.
Function
The CP 521 SI can be used for unidirectional and bidirectional data exchange.
Unidirectional Data Exchange
For unidirectional data traffic, the CP 521 is provided with a printer driver. If the printer driver is
used, the following must be connected to the serial interface of the CP 521 SI:
• A printer with TTY interface (active) or
• A printer with V.24 (RS 232C) interface.
This enables you to log process states and process disturbances. The output of messages on the
printer does not extend the response time of the programmable controller.
The following messages and texts can be output:
• Message texts, which you have configured on a memory submodule in data blocks DB 2 to 63.
• Time of day and date, which are provided by the module's own clock
• Values for variables which are transmitted to the CP 521 SI via the I/O bus.
The message texts are stored on an EPROM or EEPROM memory submodule (up to 8/16 Kbytes).
Bidirectional Data Exchange
The following drivers are implemented for the bidirectional data exchange:
• ASCII driver, transparent
• ASCII driver, interpreting mode I and interpreting mode II
• "3964(R)" driver
• SINEC L1 driver, master (point-to-point)
• SINEC L1 driver, slave
• Terminal driver
The use of these drivers enables the transmission of data frames between the CPU and an I/O
device connected to the CP 521 SI.
EWA 4NEB 812 6120-02b
Function Modules
15-63