The MultiCon series devices are advanced meters, controllers and recorders closed in one compact case. They have been designed for both advanced and less demanding applications in industrial automatic control engineering. They feature a colour TFT display with a touch screen (3.5 on the CMC-99 or 5.7 inch on the CMC-141). Such a GUI is a pleasure to work with, and the operation of the MutiCon playing the HMI role is intuitive and comfortable. The kernel of the software is LINUX operating system, which ensures stable operation and enables installing advanced software.
At first glance, the absence of any keys on the instrument front panel comes as a surprise. However, operation using the touch screen is much more efficient and comfortable. The operation philosophy is analogous to generally known windows systems: hitting (clicking on) appropriate menu keys, sliders to move the screens, etc. If, however, you are not happy with the touch screen, a traditional keyboard and a mouse can be connected to the instrument through USB ports to make the operation extremely simplified.
Despite its compact dimensions the instrument has huge application possibilities. A well-thought-out modular design allows precise adaptation of the CMC to various specific needs and requirements of all customers. Available is a wide array of input and output modules (current, voltage, universal, thermocouple, RTD, digital, counting, relay, SSR and other).
In its most expanded version, a single, compact CMC-99 instrument can include modules which provide in total up to 48 physical inputs and outputs (analogue, digital and relay). Its slightly bigger brother, CMC-141, can have fifty percent more inputs and outputs. Figure 2 shows the CMC-99 rear panel for one of the most typical configurations often ordered by our customers.
You do not need to use all slots; what’s more, when a modification becomes necessary all you need to do is send the instrument to our factory and we will introduce the changes, adding, removing or replacing modules.
The most demanding users, for whom a single RS-485 interface in the standard version is not enough, can choose the ACM (Advanced Communication Module) with additional communication interfaces: Ethernet, USB, RS-485 and RS-232 shared with another RS-485.
Using the Modbus RTU, the MultiCon CMC can read data and control outputs of other devices in the network. External inputs/outputs (i.e. inputs and outputs for other devices) are particularly useful when there is a need to control a large number of physical execution units or collect data from distant sources. The number of these inputs/outputs is counted independently of the inputs/outputs available on the built-in modules. This additionally augments the potential of MultiCon which is powerful already. In this way, using a MultiCon CMC you can build an advanced network system where you can monitor the operation of the whole from any place on the planet, e.g. via Internet.
Each MultiCon can work also as a data recorder. Its internal memory of 1.5 GB is sufficient for over 125 million of samples, meaning that even in the intensive sampling mode (every second) you can record data, for example, from 24 channels for 2 months.
Block internal design
In order to understand why such a small device meets so many different requirements, it is necessary to have a closer look at its internal design. The heart of the device is a powerful, 32-bit ARM9 processor to which typical peripherals are connected: flash memory with firmware, flash memory for data recorder, RAM, TFT graphic display with a touch screen, power supply systems, basic communication interfaces, etc.
Please note, however, the way the I/O modules are connected. To reduce the load on the CPU and ensure fast implementation of system tasks, including immediate response of the TFT display (the laboratory tests of hardware possibilities have proved that e.g. viewing films or cooperation with a USB internet camera with advance processing and image displaying in real time is not a problem), all optional measurement and communication modules are equipped and supported by their own efficient RISC processors (AVR family) and they are connected with the main processor via a fast serial bus. Therefore, all tasks related to e.g. A/D processing, calibration, transmission frames support, etc. are performed directly on the modules. As a result, even with the maximum number of modules connected, the device speed is not affected, and expanded internal firmware of the modules ensures very good accuracy and stability of measurements.
Such a design solution allows also an easy introduction of a very important element: galvanic separation of all external connections in all modules to significantly increase the device functionality and flexibility.
After powering on, the operating system is loaded from the flash memory to RAM, followed by the application software. The before-mentioned, specially designed bus connecting the modules, including an internal communication protocol, allows an immediate detection, identification and recording of each newly installed module. Suitable configuration modules are activated simultaneously which ensures full implementation of the PnP function.
The device system is based on Linux, which allows – with suitably thought-out software – to use MultiCon to implement even many independent tasks at the same time (also in large multi-channel systems).
For detailed description of more interesting software functionalities (including logical channels, mathematical operations on channels, timers, profile generators, single and multiple PID controllers, etc.) please refer to part III of the articles on MultiCon CMC. As a result of cooperation with the users, the software is constantly developed and new, useful functions are added. Interesting additions or solutions are quickly implemented as firmware updates. A free update feature is provided so that all MultiCon CMC users always have the latest firmware version installed on their devices. The update procedure cannot be simpler: just download the latest files from our website, write them on a pendrive, connect the pendrive to CMC and start the process – the rest is fully automatic.
For more information on the CMC-99 and CMC-141 from the Multicon family please visit the website page here: http://goo.gl/kAb1e