LDSYN-101工业自动化卡件
对于IMFEC11模块（FSK通信）微处理器通过模块通信电路向发射机发送命令信号。该电路将来自微处理器的命令转换为FSK信号。微处理器将命令传输引导到正确的信道。MFP模块通过I/O扩展器总线与FEC模块通信。Elsag Bailey设计的集成电路将微处理器连接到I/O扩展器总线。所有MFP命令和过程数据都通过I/O扩展器总线接口和先进先出输入或输出。模块输入/输出电路IMFEC11/12模块的过程输入可以是4至20毫安和±10 VDC的标准模拟信号；或模拟（点对点）或频移键控数字信号（在现场总线上）（IMFEC11）。模块输入电路为过程数据输入提供两条路径。一条路径处理标准模拟输入和模拟点对点输入。当IMFEC11模块处于现场总线模式时，另一条路径处理FSK数字信号。IMFEC11上的板载跳线设置操作模式。注：在现场总线模式下，IMFEC11模块最多可处理15个变送器。STT03型终端最多可在单个现场总线上编程八个变送器。有关更多信息，请参阅STT03型智能变送器终端说明
模拟输入（点对点模式）
所有模拟输入都是点对点的。每个通道都有一个模拟输入滤波器，在数据进入模数转换器（ADC）之前，该滤波器将通信信号与过程数据（模拟输入）分离。在FSK通信模式（IMFEC11）中，FSK数字通信信号依赖于模拟输入信号的一小部分。该输入还通过FSK通信电路进行解码。微处理器通过多路复用器协调点对点输入和输出的操作。图2-2显示了典型的模拟输入滤波器电路。电路通过P3连接器连接到FEC终端（点对点）。每个模拟输入具有过压保护，以保护电路。模拟信号通过两个低通滤波器，将通信与数据分开。微处理器将滤波后的输入信号（过程数据）多路复用到ADC电路进行转换。FEC模块在每个输入通道上以每秒五次的速度连续进行模数转换。将模拟信号转换为数字等效信号后，FEC模块将该值存储在存储器中。在点对点模式下，FEC模块可以输入4至20毫安或-10至+10 VDC。功能代码132允许为每个信道选择信号类型。
For IMFEC11 modules (FSK communications)
the microprocessor sends command signals to the transmitters through the module communication circuitry. The circuitry converts commands from the microprocessor into FSK signals. The microprocessor directs the command transmission to the proper channel. The MFP module communicates with the FEC module over the I/O expander bus. An Elsag Bailey designed integrated circuit interfaces the microprocessor to the I/O expander bus. All MFP commands and process data pass through the I/O expander bus interface and first in first out inputs or outputs.Module Input/Output Circuitry Process inputs to the IMFEC11/12 modules can be standard analog signals of four to 20 milliamps and ±10 VDC; or analog (point-to-point) or frequency shift keyed digital signals (on a field bus) (IMFEC11). The module input circuit provides two paths for process data inputs. One path handles standard analog inputs and analog point-to-point inputs. The other path handles FSK digital signals when the IMFEC11 module is in the field bus mode. On-board jumpers on the IMFEC11 set the operating mode. NOTE: In field bus mode, the IMFEC11 module can handle up to 15 transmitters. The Type STT03 terminal can program a maximum of eight transmitters on a single field bus. Refer to the Smart Transmitter Terminal, Type STT03 instruction for more information
ANALOG INPUTS (POINT-TO-POINT MODE)
All analog inputs are point-to-point. Each channel has an analog input filter that separates the communication signal from the process data (analog input) before the data goes to the analog-to-digital converter (ADC). In the FSK communication mode (IMFEC11), the FSK digital communication signal rides on a small portion of the analog input signal. That input also passes through the FSK communication circuitry for decoding. The microprocessor coordinates operation of point-to-point input and output through multiplexers. Figure 2-2 shows a typical analog input filter circuit. The circuit connects to the FEC termination (point-to-point) through the P3 connector. Each analog input has overvoltage protection to protect the circuitry. The analog signal passes through two low pass filters that separate communication from data. The microprocessor multiplexes the filtered input signal (process data) to the ADC circuitry for conversion The FEC module does analog-to-digital conversions on each input channel continuously at five times per second. After converting the analog signal to a digital equivalent, the FEC module stores that value in memory. When in the point-to-point-mode, the FEC module can input four to 20 milliamps or -10 to +10 VDC. Function code 132 allows selecting the signal type for each channel.
