Siemens SIMATIC S5 CP 521 Manual page 15

Overview
System
In print mode, the CP 521 assumes a printer with a RS-232-C (V.24) or active TTY
interface. The printout of message texts does not increase the res~onse time of
the programmable controller. You can have the following printed out:
Texts configured by the user on a memory submodule (data blocks 2
Time of day and date from the module's own real-time clock.
. Values for variables to be transferred via the 1/0 bus to the CP 521.
Figure 1-1. Complete Configuration: A Programmable Controller with a CP 521
and Printer
1 2
to 63).
GWA 4NEB 812 6030-02b