Top 10 PLC Manufacturers and Specifications of Siemens

This document provides information about the top 10 PLC manufacturers, including Siemens, and their specifications. It also covers the product lifecycle and the difference between regular entry level PLC and safety PLC.

1) Top 10 PLC Manufacturers:
1) Siemens
2) ABB
3) Emerson Process Management
4) Rockwell automation
5) Schneider Electric
6) Honeywell process solutions
7) Mitsubishi electric
8) Yokogawa electric
9) Omron automation
10) Danaher Industrial Ltd
2) Specifications of Siemens:
 Siemens utilizes the PLC software known as SIMATIC WinAC software PLC where the PC
based controllers are coupled with the rugged and open architecture. The PC based
controllers are configured and programmed with the STEP 7 in the same way of the S7
controllers (Puchun & Jinhai, 2009). The first failsafe software of Siemens PLC is said to
be the SIMATIC WinAC RTX F with the TUEV Certification.
 An application wizard is included in SIMATIC WinAC ODK (Open Development Kit) and
the simple programming can be done (C, C++) with the class library in the Microsoft
Visual Studio. The program that runs out of the WinAC is developed with the Visual C#
(for the windows appliction), which is generated as Real-time DLL with 3 system
functions (SFC 65001, 65002, 65003)
 SIMATIC WinCC is a scalable process visualization system (SCADA) that is highly efficient
for controlling and automating process. Sufficient integration scalability is provided by
SIMATIC WinCC that offers small single-user solution, client/ server solution web-based
and Redundancy server solutions for the higher security and availability purposes.
 The fastest SIMATIC S7-400 CPU speed is said to be 450 MHZ with the multiprocessor
system.
 SIMATIC S7-400 could operate both program and data memory simultaneously. For the
small and the medium sized programs, integrated memory called RAM is used. For large
programs the size could be increased by slotting an extra RAM. The program memory
sizes are as follows:
 CPU 412-1: 72 KB
 CPU 412-2: 128 KB
 CPU 414-2: 256 KB

 CPU 414-3: 700 KB
 CPU 416-2: 1.4 MB
 CPU 416-3: 2.8 MB
 CPU 417-4: 10.0 MB
3) Product Lifecycle:
The product lifecycle phase has been included in the Product Lifecycle Management (PLM) and
the differentiation has been bought out among the core components as well as the product
accessories.
 "Announcement of Product Phase out" and "Product Cancellation" is not used for the
SIMATIC HMI accessories and the core components run through all of them (Jung,
2008). They can be ordered on the normal basis and they are available on the complete
lifecycle.
 The accessories of SIMATIC HMI products have a lifetime of 22 years.
4) Difference:
Regular entry level PLC Safety PLC
They could cause unsafe condition in
hazardous condition
It is designed in such a way that the failure will
not cause an unsafe condition
They do not have redundancy (backup). They
have 1 microprocessor to execute the
program, with the ports and I/O module for
communication and controlling the machine,
RAM for performing calculations and Flash
area to store the program
They have redundant processors with the
watchdog circuit, I/O communications that
could save the entire control system during
the hardware or software failures (Moller et
al, 2008).
There is no input circuit testing functionality
internally.
They have an internal ‘output’ circuit along
with individual input for ‘exercising’ the input
circuitry.
They have a single Output switching device. A test point is included in the output logic of
the digital circuit and the output driver is
comprised of two safety switches. The output
driver has a third test point downstream. Each
of these safety switches are controlled by a
microcontroller.
References:
"PLC – Ladder Logic." Automation Studio™ Educational Edition. Famic Technologies Inc. Web.
<http://www.famictech.com/edu/index.html>

Jung, I., (2008). “PLC Control Logic Error Monitoring and Prediction Using Neural Network”,
Natural Computation, ICNC '08. Fourth International Conference, 2(6), pp. 484 – 488.
Moller T., et al.(2008). “PLC based control of remote laboratory experiments”. 2008 11th
International Biennial Baltic Electronics Conference, IEEE, pp. 273-276.
Puchun, A., & Jinhai, L. (2009). A PLC-Based Data Acquisition System with Adaptive Threshold
Algorithm for Leak Detection of Oil Pipeline. Chinese Automation Congress
(CAC),10.1109/CAC.2013.6775843, pp. 801-805.