IC754VGF12CTD internal memory 64 MB flash panel

Description

IC754VGF12CTD is manufactured by GE Automation&Controls and is a display panel computer in the QuickPanel series. This device has a 12 inch (30.5 cm) TFT touch screen that can display 65536 colors at a rate of 16 bits per pixel. The touch screen resolution is 800 X 600 pixels. The stylus pointer is used to interact with touch screen displays; However, external mice and keyboards can also be supported through USB connections. The USB drivers for these devices are included in the operating system.

IC754VGF12CTD adopts Microsoft’s Windows CE operating system. Windows CE runs on a 32-bit architecture and uses the standard Win32 application programming interface. The Windows CE operating system is equipped with various applications and programs, including web browsing software, registry and flash backup programs, storage manager software for formatting and installing drive partitions, and transferring files between compatible hosts. The device can also view Excel, PDF, and Word documents.

IC754VGF12CTD has two serial ports. COM1 is the DP25S female head, and COM2 is the DP9P male head. The data transmission rate range of the two serial COM ports is 300 to 115200 bits per second (bps). The tablet also provides two Ethernet ports, equipped with standard unshielded twisted pair CAT5 cables and RJ-45 connectors. These Ethernet ports support half duplex or full duplex communication and require all connected devices to use automatic negotiation.

The technical characteristics and mutual penetration of DCS and PLC have different conceptual foundations and development paths, which make DCS and PLC have their own unique technical characteristics. The development of technology is not closed, and mutual learning and infiltration always run through the development process.

We know that a PLC controller can often handle thousands of I/O points (up to over 8000 I/Os). The controller of DCS can generally only handle hundreds of I/O points (no more than 500 I/Os). Is it because the technical level of DCS developers is too poor? I’m afraid not. From the requirements of a distributed system, it is not allowed to have centralized control. Controllers with too many points are useless in practical applications. DCS developers do not need to drive controllers with many I/O points, and their main focus is on providing the system with reliability and flexibility. PLC, on the other hand, is different. As an independent flexible control device, the stronger the point capability, the higher its technical level. As for the application level of the entire control system, this is mainly a matter for engineering companies and users, rather than the core goal of PLC manufacturers.

Another indicator of control processing ability, the calculation speed, is also much faster in people’s impression than DCS. From a certain perspective, the situation is indeed the same. The efficiency of PLC executing logic operations is very high, with less than 1 millisecond of executing 1K logic programs. Its control cycle (taking DI input directly sending DO output as an example) can be controlled within 50ms; DCS, on the other hand, uses the same method for handling logical and analog operations, with a control cycle often exceeding 100ms. When we use the PID algorithm to compare, it can be found that the PLC performs a PID operation in a few milliseconds, while the T2550 controller of NT6000DCS also takes 1 millisecond to solve a PID. This indicates that the computing power of PLC and DCS is equivalent to the actual operation, and a certain type of DCS controller is even stronger. The difference in control cycle is mainly related to the scheduling design of the controller.

Large PLCs often use auxiliary CPUs to complete analog operations, while the main CPU completes switch operations at high speed. Therefore, even if the analog operation speed is average, the speed performance in switch control is still very excellent. However, when DCS processes switching and analog operations at the same speed, the control cycle index is indeed not ideal. The new DCS controller has learned the design of large PLCs and achieved significant improvement in control cycle performance. Taking the T2550 controller of NT6000DCS as an example. The controller can set four tasks with different priorities, and the minimum calculation cycle can be set to 10ms. With high-speed I/O cards, the control cycle can reach 15-20ms. Analog operations are set in other tasks with longer cycles.
Data communication exchange mainly refers to the control system network and its data exchange form. DCS has inherent advantages in this regard. The “decentralization” of distributed systems is mainly reflected in independent controllers, while the “centralization” is mainly reflected in human-machine interaction devices with complete data, and it is the network that connects the decentralization and centralization into the distributed system. Therefore, from the early development of DCS, network has become the core technology direction of DCS manufacturers, and redundancy technology and narrowband transmission technology are the earliest successful research and application of DCS manufacturers. PLC is mainly designed according to independent devices, and its “network” is actually serial communication. The development and widespread application of industrial Ethernet technology have bridged the gap between DCS and PLC networks in terms of form. On the surface, many DCS and PLCs have applied industrial Ethernet, but there is still a qualitative gap. Take the MODBUS-TCP used by many PLCs as an example.

MODBUS is a serial communication protocol, not a network, no one has any doubts; Is MODBUS-TCP a network? Many people have doubts. Upon careful analysis, MODBUS-TCP is a communication method that loads the MODBUS communication protocol onto the TCP protocol of Ethernet. Although it has the appearance of a network, it still has a management mode of one master and multiple slaves, and a data table transmission structure. As for DCS, taking the ELIN network of NT6000 as an example, although it is also based on industrial Ethernet, its application layer protocol is the ownerless token LIN network protocol that has been accumulated for nearly 30 years. It has been successfully applied in 1M OLIN, 2.5M, and 20M ARCNET for a long time. On ELIN, all stations are equal and there are no major management stations. Moreover, data communication is structured data on a module by module basis, and data management capabilities are comparable to non data table methods.

Taking the PID module as an example, the basic data includes PV, SP, and OP. Using a data table transmission method, you must first define the data addresses of PV, SP, and OP as 01, 02, and 03. Other stations also receive data in a data table format, but what data is 01? What data is 02? The data definition table must be used to restore. The management method of data tables is cumbersome and prone to errors. Using this method to manage tens of thousands of points of data in a large system and flattening them in a data table is very frightening. NT6000DCS, on the other hand, uses modular structured management to process a PID as a module. To access its PV value, the module is first accessed and managed in the form of PID. PV. This centralizes all tiled data into small boxes for classification and attribution, and manages them in a modular and component manner, greatly improving management efficiency. The problem of PLC data communication and exchange mainly stems from the long-term development of PLC as an independent device without a system concept; Moreover, it is mainly applied in small control systems, and the problems are not clearly exposed, so the development is slow. At present, there are also some large PLCs that have improved in this area, but it will take a considerable process to reach the level of DCS.