LDSYN-101工業(yè)自動化卡件
對于IMFEC11模塊（FSK通信）微處理器通過模塊通信電路向發(fā)射機(jī)發(fā)送命令信號。該電路將來自微處理器的命令轉(zhuǎn)換為FSK信號。微處理器將命令傳輸引導(dǎo)到正確的信道。MFP模塊通過I/O擴(kuò)展器總線與FEC模塊通信。Elsag Bailey設(shè)計(jì)的集成電路將微處理器連接到I/O擴(kuò)展器總線。所有MFP命令和過程數(shù)據(jù)都通過I/O擴(kuò)展器總線接口和先進(jìn)先出輸入或輸出。模塊輸入/輸出電路IMFEC11/12模塊的過程輸入可以是4至20毫安和±10 VDC的標(biāo)準(zhǔn)模擬信號；或模擬（點(diǎn)對點(diǎn)）或頻移鍵控數(shù)字信號（在現(xiàn)場總線上）（IMFEC11）。模塊輸入電路為過程數(shù)據(jù)輸入提供兩條路徑。一條路徑處理標(biāo)準(zhǔn)模擬輸入和模擬點(diǎn)對點(diǎn)輸入。當(dāng)IMFEC11模塊處于現(xiàn)場總線模式時，另一條路徑處理FSK數(shù)字信號。IMFEC11上的板載跳線設(shè)置操作模式。注：在現(xiàn)場總線模式下，IMFEC11模塊最多可處理15個變送器。STT03型終端最多可在單個現(xiàn)場總線上編程八個變送器。有關(guān)更多信息，請參閱STT03型智能變送器終端說明
模擬輸入（點(diǎn)對點(diǎn)模式）
所有模擬輸入都是點(diǎn)對點(diǎn)的。每個通道都有一個模擬輸入濾波器，在數(shù)據(jù)進(jìn)入模數(shù)轉(zhuǎn)換器（ADC）之前，該濾波器將通信信號與過程數(shù)據(jù)（模擬輸入）分離。在FSK通信模式（IMFEC11）中，F(xiàn)SK數(shù)字通信信號依賴于模擬輸入信號的一小部分。該輸入還通過FSK通信電路進(jìn)行解碼。微處理器通過多路復(fù)用器協(xié)調(diào)點(diǎn)對點(diǎn)輸入和輸出的操作。圖2-2顯示了典型的模擬輸入濾波器電路。電路通過P3連接器連接到FEC終端（點(diǎn)對點(diǎn)）。每個模擬輸入具有過壓保護(hù)，以保護(hù)電路。模擬信號通過兩個低通濾波器，將通信與數(shù)據(jù)分開。微處理器將濾波后的輸入信號（過程數(shù)據(jù)）多路復(fù)用到ADC電路進(jìn)行轉(zhuǎn)換。FEC模塊在每個輸入通道上以每秒五次的速度連續(xù)進(jìn)行模數(shù)轉(zhuǎn)換。將模擬信號轉(zhuǎn)換為數(shù)字等效信號后，F(xiàn)EC模塊將該值存儲在存儲器中。在點(diǎn)對點(diǎn)模式下，F(xiàn)EC模塊可以輸入4至20毫安或-10至+10 VDC。功能代碼132允許為每個信道選擇信號類型。
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.
