HONEYWELL FTA-T-14使用在哪里,FTA-T-14模塊
功能框圖VMIVME-3112板的框圖如圖1.2-1所示這說明了電路板的組件及其功能。未顯示在方框圖是提供模擬電源的直流-直流轉(zhuǎn)換器（±15 V）。用戶只需向電路板提供+5 V電壓。引言
VMIVME-3112是一個64通道、12位模擬輸入板。這個電路板具有許多內(nèi)置功能，因此可以處理許多數(shù)據(jù)采集問題。例如，自動掃描模式打開通電可方便編程。在自動掃描模式下通道持續(xù)數(shù)字化并存儲在雙端口寄存器中。任何渠道可能隨時讀取以獲取最新數(shù)據(jù)。VMIVME-3112是一種靈活、低成本的模擬輸入板具有許多競爭產(chǎn)品中沒有的功能。這些本節(jié)討論了功能。
HONEYWELL FTA-T-14使用在哪里3.2內(nèi)部職能組織VMIVME-3112分為以下功能類別，如下所示：如圖3.2-1所示。詳細(xì)討論了所有VMIVME-3112函數(shù)本節(jié)。
a、 VMEbus接口b、 模數(shù)轉(zhuǎn)換器（ADC）和控制邏輯
c、 模擬輸入濾波器和多路復(fù)用器d、 可編程定時器
e、 總線斷路器f、 板ID寄存器總線控制接口
VMIVME-3112通信寄存器的內(nèi)存映射為128（十進(jìn)制），16位字。寄存器是連續(xù)的，用戶可以位于VMEbus的短輸入/輸出地址空間內(nèi)的任何256字節(jié)邊界。這個電路板可以由用戶配置為響應(yīng)短路或短路非特權(quán)總線通信或兩者兼有。在每次讀或?qū)懖僮髌陂g，所有VMEbus控制信號均為忽略，除非電路板選擇比較器檢測到車載選擇跳線如圖3.3-1所示，以及地址和地址背板的修改線。如果出現(xiàn)以下情況，則會出現(xiàn)適當(dāng)?shù)亩聲憫?yīng)：檢測到有效匹配，然后打開采集器DTACK接口信號斷言（驅(qū)動低）。隨后刪除總線主機(jī)的讀寫操作命令使板生成的DTACK信號返回到關(guān)閉狀態(tài)。
FUNCTIONAL BLOCK DIAGRAM
A block diagram of the VMIVME-3112 Board is shown in Figure 1.2-1
which illustrates the board's components and their functions. Not shown on the
block diagram is a DC-to-DC converter which provides the analog power supplies
(±15 V). The user has only to supply +5 V to the board. INTRODUCTION
The VMIVME-3112 is a 64-Channel, 12-Bit Analog Input Board. The
board has many built-in features, resulting in a board that is capable of handling
many data acquisition problems. For example, the AUTO SCANNING MODE on
power-up allows for ease of programming. In AUTO SCANNING MODE each
channel is continually digitized and stored in a dual port register. Any channel may
be read at any time to get the latest data. The VMIVME-3112 is a flexible, low-cost
analog input board with features not found in many competing products. These
features are discussed in this section.
3.2 INTERNAL FUNCTIONAL ORGANIZATION
The VMIVME-3112 is divided into the following functional categories, as
illustrated in Figure 3.2-1. All VMIVME-3112 functions are discussed in detail in
this section.
a. VMEbus Interface
b. Analog-to-Digital Converter (ADC) and Control Logic
c. Analog Input Filters and Multiplexer
d. Programmable Timer
e. Bus Interrupter
f. Board ID RegisterVMEbus CONTROL INTERFACE
The VMIVME-3112 communication registers are memory-mapped as 128
(decimal), 16-bit words. The registers are contiguous and may be user-located on
any 256-byte boundary within the short I/O address space of the VMEbus. The
board can be user-configured to respond to either short supervisory or
nonprivileged bus communications or both.
During each read or write operation, all VMEbus control signals are
ignored unless the board-selection comparator detects a match between the
on-board selection jumpers shown in Figure 3.3-1, and the address and address
modifier lines from the backplane. The appropriate board response occurs if a
valid match is detected, after which the open collector DTACK interface signal is
asserted (driven LOW). Subsequent removal of the bus master's read or write
command causes the board-generated DTACK signal to return to the
OFF state.
