VersaMax Processor Selection Guide

I. INTRODUCTION
The VersaMax Programmable Logic Controller (PLC) platform is an industry recognized industrial automation product known for its technical features that meet the industrial operating requirements and standards. Originally released in 1998 by GE Fanuc, the VersaMax platform is now under Emerson Automation. Along with the change in name, comes controller enhancements mostly, with the capabilities of the controler. Most importantly, the VersaMax product line remains an active product.  

This article is meant to provide the basic knowledge in selecting processor for a VersaMax control system. As widely known, the PLC controller is the most expensive part of a PLC system. It is just fitting to have a dedicated selection guide for this PLC Platform.  

II. The VersaMax Programmable Logic Controller (PLC)
The VersaMax Platform is a family of Programmable Logic Controller (PLC) that is available in Four (4) forms – Nano, Micro, Micro Plus and Modular types.

A. Compact Controllers
VersaMax compact controllers features the Nano, Micro and Micro Plus Range of controllers. These controllers are ideally used in small applications and processes and may also be used in low-end, low axis count motion control applications. Nano and Micro VersaMax PLCs are highly suitable for industrial machines such as Material Handling, Packaging, Converting, Conveyor control and industries such as Water and Waste Water, Construction equipment and Chemical industries. These controllers come with integrated Power supply, CPU, I/O channels and communication interface.

Specific features of compact controllers can be identified in the table below:

VersaMax Nano controllers have a maximum of 11 I/O points while VersaMax Micro and Micro Plus controlelrs ranges from 14-pt to 40-pt modules however, Only the Micro Plus controller support installation of 64-pt I/O expansion module.

B. Modular Controllers
VersaMax modular controllers are ideally used in Medium to Large size applications. Each component of this PLC type is separately purchased allowing for a more custom designed control system.

III. VersaMax Processor Selection

To properly select a VersaMax controller, one needs to primarily identify the size of the application and the level of criticality that must be met. Identification of this requirement significantly simplifies the processor selection process.

A. Size of application
Identification of the application size leads to selection whether to use Compact and Modular VersaMax PLC. This can be determined by referencing the I/O count.

If the I/O density is within the 256 I/O count, the process may be controlled with the use of Compact VersaMax PLC. With an application exceeding 256 I/O count, specifically, 256 – 1024 I/Os, a Modular

VersaMax processor may be used. Beyond 1024 I/O range, Modular VersaMax controller may still be used.

B. Criticality of application
The level of criticality of an application may require designing of a hot-swappable modules, redundant controller architecture, redundant communication network and redundant I/O system. Depending on the system, a specific redundancy may be implemented. 

Typically, compact controllers cannot comply to the redundant configurations previously mentioned. Conversely, with the highly-customizable hardware of modular controllers, these controller type are compliant to these redundancies.

Specifically, the VersaMax modular controllers supports hot-swap modules, Media system redundancy and I/O redundancy.

C. Analog loop control
Industrial processes are not limited to discrete operations only. With the increasing demand for accuracy and efficiency, analog control loops are necessary to implement multiple points, continuous control compared to discrete On/OFF control. With this requirement, it is important to identify as well if the selected processor supports analog data processing.

VersaMax Micro, Micro Plus and Modular controllers support analog data processing while Nano controllers can only accept a single analog input signal and unable to deliver an analog output signal which is necessary to control an analog loop.   

D. Controller memory and processing speed
This criterion is highly applicable to Modular VersaMax controllers. With only 4 controllers available for selection and identical support to the same number of I/O density of 4096 I/O points, selection of controller memory is decided by the I/O combination and application speed.

If majority of the I/Os are discrete in nature, lesser controller memory will be consumed compared to a control system with majority of analog I/Os (refer to table 8). Additionally, if the system is composed of common electrical devices and fields instruments, this would mean that the process is pretty much a general type of application. One may need a faster processing speed if the control system deals with high-speed devices, used in motion control applications and other high-efficiency and fast response systems.

For instance, assuming that the system maximizes 4096 Discrete I/Os, the total number of controller memory consumed by the I/Os alone is 512 Bytes only.

Similarly, if all of the 4096 supported I/O channels are 16-bit resolution analog I/O, up to 8192 or 8.2KB of controller memory will be consumed as shown in table 10. 

It is important to note that these computations are the consumption of physical I/O alone. One must take into consideration the system overhead, the complexity of the program, the programming instructions to be utilized as well as the internal memory bits to be used when developing the user program. Referencing to the I/O computation alone, it can be summed up that the IC200CPU001 CPU with Two Serial Ports, 34kB of Configurable Memory, the most basic VersaMax modular controller still has more than sufficient memory left to handle other processes that consume memory. 

E. I/O scalability
I/O scalability refers to the capability of the control system of being installed with additional I/O modules whether during the project development and commissioning stage or future enhancements. This feature not only focuses on the number of I/O that can be added but the supported architecture that can be implemented when scaling up the control system.

Naturally, I/O scalability is greatly supported by the VersaMax modular controllers as these controllers support a larger density of I/O count compared to any of the compact VersaMax controllers. 

Referring to Table 11, I/O density support, it can be seen that VersaMax Micro and Micro Plus can support up to 140 and 320 I/O respectively, including the expansion units. However, this are local I/O expansions only using up to Four additional I/O (4) modules. With Modular controllers, up to 4096 I/O may be achieved using a combination of I/O scaling methods such as:

– Local Expansion
– via Expansion units
– Remote I/O units

Local expansion is similar to the supported methods of Micro and Micro Plus PLCs – modules are installed to the rack where the CPU resides. I/O scaling using expansion units allows expansion of up to 7 additional groups of I/O modules where each group may contain up to 8 I/O modules. Additional groups may be separated to the CPU up to a maximum distance of 2460 feet or 750 m.

Another method of scaling up the I/O of a modular controller is through the use of Remote I/O units. Remote I/O units permit implements a somewhat similar method compared to the expansion units however, the maximum distance, connection topology and transmission speed depends on the protocol used. Remote I/O supports PROFINET interface, as well as Genius, PROFIBUS-DP, and DeviceNet communication standards. The maximum distance that can be covered by Remote I/O architecture are 100 m with Profinet; 500 m with DeviceNet; 2286 m with Genius and 1200 m with ProfiBus DP. Additionally, distance may be extended with the use of media converters and repeater modules.

F. Communication
Communication capability of a controller is another main criterion when selecting a processor. Normally, any PLC is provided with a base communication port to allow the controller to communication with the programming device and to be partnered with a Human Machine Interface (HMI) or Supervisory Control and Data Acquisition (SCADA). In the case of VersaMax controllers, the typically provided communication port is an RS232 serial port. As the controller increase in feature, the communication Is upgraded as well. Refer to table 13 below:

It can be summarized that only the VersaMax IC200CPUE05 Modular controller comes with a built-in Ethernet communication interface. With the advent of Industrial Internet of Things (IIOT), an etehrnet interface is ideal however, other VersaMax modular controllers may be installed with an optional communication module that supports ProfiNet and Ethernet. This is also true with VersaMax Micro Plus 20/40/64 Compact controllers.

It is also worth mentioning that the configurable system protocol of the embedded serial ports are SNP slave and RTU slave communications.

Tags: Versamax, Versamax hardware

This entry was posted on May 21st, 2021 and is filed under GE Fanuc, Hardware Comparison, PLC. Both comments and pings are currently closed.