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System Overview
SIMATIC 545/555/575 System Manual
The newer model 555 and 575 CPUs incorporate several new features and
enhancements, including the following:
•
The 555–1105/–1106 CPUs and 575–2105/–2106 CPUs include a
built-in Motorola 68882 floating-point math coprocessor.
•
The 555–1105/–1106 and 575–2105/–2106 CPUs support PowerMath
t
functionality, which compiles high-level math functions using the new
memory type allocation of Compiled Special (CS) memory for Special
Function (SF) programs and SF subroutines. Compiled SF programs
and SF subroutines can be marked for “in-line” execution within your
relay ladder logic (RLL) program.
(Refer to the SIMATIC 545/555/575 Programming Reference User
Manual or the release notes that are shipped with your CPU for more
information about PowerMath and other CPU-specific features.)
•
SmarTune
t
built-in automatic PID loop tuning is supported in the
555–1105 and 555–1106 CPUs.
•
The standard PID loops have increased from 64 to 128 on the 555–1105
and 555–1106 CPUs. The 555–1105 and 555–1106 CPUs also support
an additional 128 “fast” user-scheduled PID loops.
•
Analog alarms have increased from 128 to 512 on the 555–1105 and
555–1106 CPUs.
•
Faster local-port baud rates of 57,600 and 115,200 baud are supported
in the 555–1105/–1106 and 575–2105/–2106 CPUs. These baud rates
allow faster program loading and operator panel updates.
•
Operating system firmware is stored in on-board, permanent flash
memory, which allows you to make future firmware release upgrades
using floppy disks or file transfer over the Internet.
•
The 545 and 555 CPUs have the option of storing user program
memory in larger capacity on-board EEPROM in addition to the
portable EEPROM option.
•
The new 575 CPUs support program storage in on-board EEPROM.
•
The 545 and 555 CPUs now incorporate a front-accessible back-up
battery which can be replaced while the CPU is powered and running.
The battery is rated to retain program memory (with the system
powered off) for 3 years at room temperature (25
°
C) and for 6 months
at elevated temperature (60
°
C).
•
The PROFIBUS-DP port is now integrated on the board rather than on
an annex card with the 545–1106 and 555–1105/–1106 CPUs.
Features on New
CPU Models
