Industrial Control Keeps Getting Better

The changes in PLCs and PACs aren’t so much in operational, but in networking, user interface, and compute horsepower.


Better at reaching out
Once upon a time, a factory-wide Ethernet local area network (LAN) was, if not rare, approached tentatively. Replacing a proprietary network with Ethernet required installing an expensive Ethernet card. No longer. The new 20-point Micro820 programmable logic controllers (PLC) from Allen-Bradley ( has embedded Ethernet and serial ports. Along those lines, General Electric ( recently debuted three new programmable automation control (PAC) PACSystem RX3i modules to provide IEC61850, DNP3, and IEC60870-5-104 Ethernet-based communication for “in-rack” systems. The modules also support fiber optic networking without external converters. At the very least, the modules help improve access to data and to time-stamping events using object-oriented programming. Rachael Conrad, business manager, Networks and Security, Rockwell Automation, points out two more reasons why manufacturers are migrating to standard EtherNet/IP networks. First, “EtherNet/IP has increased the recognition of the importance of a secure environment from the enterprise down to the end devices. [Second] to better leverage technologies and capabilities, such as big data, cloud computing, and virtualization.” 

However, a LAN isn’t anything without the devices it networks together. The latest Sinema Server station from Siemens Industry Automation Div. ( can monitor up to 500 devices, double that of the previous server. Each Sinema Server can display the status of up to 100 other Sinema Servers within the network, bringing the total number of clients to 50,000. Connected components are automatically identified using SNMP (simple network management protocol), and Profinet devices are identified by DCP (device control protocol). Included software displays all physical connections at the port level, as well as machine- or application-specific network configurations. Network malfunctions are flagged, including those in existing virtual LANs. Diagnostic information includes both configuration and device-identification data, such as name, device type, serial number, and product-specific status.

There’s also the wireless route. Siemens announced last year a low-cost Scalance series of modules for wireless machine networking with transmission rates up to 150 Mbps; the higher-priced series, rates up to 300 Mbps. Both comply with the IEEE 802.11n standard.

Better at visualizing operations
While the factory floor is hardly a gamer’s paradise, production control and monitoring works best with fast, high-resolution graphics. Siemens’ newest Simatic HMI Basic Panels are high-resolution widescreen displays with 64,000 colors. With screens measuring from 4- to 12-in. diagonal, these monitors come with USB interface, Profinet and Profibus DP interfaces, plus software for alarming, trend functionality, language options, and other functions.

Better, the Siemens Simatic IFP1900 MT is a 19-in. monitor (1366 x 768 pixels) with a gesture and multi-touch interface akin to tablets and cellphones. The monitor’s anti-glare glass front is scratchproof and resistant to chemicals. Operators can use it even when wearing thin gloves. The monitor responds to 1- to 5-finger touches, and automatically detects erroneous touches, such as from a person’s thumb or from floating particles.

Better at computing
Back to A-B’s Micro820 PLC. It has a slot for microSD cards up to 32 GB. This data storage is useful for transferring, backing up, and restoring programs, as well as for data acquisition. (Data files are stored in CSV text format.) The Micro820 can even be accessorized. For instance, a remote, 3.5-in., Micro800 LCD display supports up to eight lines of ASCII text and includes a keypad with programmable function keys and USB port. A new scanner plug-in module supports up to 20 nodes of A-B PowerFlex AC drives or CompactBlock LDX I/O, which helps reduce wiring costs and installation. Another new plug-in module—a high-speed counter—provides position feedback from the servo drive for position verification or, with an encoder, for position and velocity monitoring.

Siemens PLCs are also gaining features. The Simatic S7-1500 CPU 1518-4 PN/DP for high-end applications has 13 MB of RAM and four communication interfaces for Profinet and Profibus. The device has a bit performance of 1 nanosecond (ns) and can connect up to 128 drive axes with isochronous operation of about 250 microseconds. For mid-level applications, the Simatic S7-1500 CPU 1515-2 PN, with a bit performance of 30 ns, has 3.5 MB of RAM (500 Kb for programs; 3 MB for data) and two Profinet interfaces.

PACs are better, too. For instance, a single PAC with a multi-core processor can provide deterministic, real-time control on one core while another core or cores run the sophisticated visualization, data communications, and the operator interface. In addition to their processors, the latest PACs have beefed up system memory, data storage, and displays. To prove the point is the new D series of Simatic IPC PACs from Siemens. These high-end industrial PCs run on Intel Xeon and Intel Core i3 to Core i7—CPUs with fast clock speeds, multiple cores, multiple threads, large memory cache, low energy requirements, and an embedded graphics processor. These PACs have 60 to 180% higher CPU power than previous Simantic PACs; the high-definition (HD) on-board graphics that’s integrated in the Intel processor has three times the graphics performance. In fact, these processors can support 22-in. HD widescreen displays, which can cover a lot of fast instrumentation and control tasks, as well as at-machine operator control and monitoring. The D series include PCIe 3.0, DisplayPort and DVI graphics, and USB 3.0; an optional PCIe x16 video card can support up to five monitors. Intel’s integrated Active Management Technology (AMT) makes remote management easy, including password-protected remote diagnostics and maintenance. Incidentally, the Simatic IPCs can be pre-installed with Microsoft Windows 7 Ultimate (32/64 bit) operating system; the higher-end devices, with Windows Server 2008 R2. The Siemens 19-inch rack-mount equivalent is the Simatic IPC547E.