IC697CPX928-FE使用手冊,GE通用電氣模塊
兩個連接器P1和P2將VMIVME-3112板連接到VMEbus背板。連接器為96針DIN型。主連接器，P1，包含地址數據和控制線以及所有附加信號需要控制數據傳輸和其他總線功能。VMIVME-3112電路板使用四個用戶輸入/輸出引腳來允許外部觸發(fā)器輸入和狀態(tài)輸出P2連接器引腳和信號分配如圖5.6-1所示和表5.6-1。
IC697CPX928-FE使用手冊P3和P4連接器是Panduit 64針陽連接器，類型120-964-033A。輸入電纜的匹配Panduit連接器為內螺紋連接器，120-964-435E型。此連接器支持32單端或32差分模擬輸入各有一個相關的模擬接地引腳。對于P3連接器引腳和信號分配，請參閱圖5.6-2和表5.6-2。對于P4連接器引腳和信號分配，請參閱圖5.6-2和表5.6-3。P3和P4接頭有一個“A”行（A1到A32）和一個“C”世界其他地區(qū)（C1到C32）。所有“A”行引腳均為輸入信號的高端。所有“C”行引腳是輸入信號的低端。連接的首選方法模擬輸入信號用于連接每個通道的高輸入和低輸入（差速器）。差分輸入提供非常高的共模噪聲通過拒絕模擬電路之間的地電位差進行拒絕發(fā)射器和VMIVME-3112板。電路板在工廠配置為接受差分輸入。連接模擬輸入的第二種方法稱為偽差分。在這種連接方案中，只有一個接地基準被帶到并在針腳C1處連接到P3連接器。這意味著所有連接來自現場的通道必須參考同一地面。此方法具有差分輸入的一些優(yōu)點在于它有助于抑制接地差異，但在共模噪聲抑制方面不如前者。跳線J1必須安裝以啟用此模式。此外，輸入端的SIP電阻器必須處于第5.4.3.1節(jié)所述的單端位置。連接模擬輸入的第三種方法是單端輸入。這該方法使用車載模擬接地作為輸入信號參考。這是通常是三種方法中精度最低的。然而，在低噪音環(huán)境中當使用短布線時，這種方法會很好地工作。輸入必須將sip電阻器從差速器移至單端插座（參見5.4.3.1）和跳線J2必須安裝。連接器和輸入/輸出電纜應用指南（VMIC文件號。825-000000-006），可從提供額外信息的VMIC獲得關于現場連接，圓形電纜的使用，以及兼容的連接器和布線技術。
Two connectors, P1 and P2, connect the VMIVME-3112 Board to the
VMEbus backplane. The connectors are 96-pin DIN type. The primary connector,
P1, contains the address data and control lines and all additional signals
necessary to control data transfer and other bus functions. The VMIVME-3112
Board uses four of the user I/O pins to allow an external trigger input and a status
output. The P2 connector pin and signal assignments are shown in Figure 5.6-1
and Table 5.6-1.
The P3 and P4 connectors are Panduit 64-pin male connectors, type
120-964-033A. The matching Panduit connector for the input cable is a female
connector, type 120-964-435E. This connector supports the 32 single-ended or 32
differential analog inputs each with an associated analog ground pin. For P3
connector pin and signal assignments, refer to Figure 5.6-2 and Table 5.6-2. For
P4 connector pin and signal assignments, refer to Figure 5.6-2 and Table 5.6-3.
The P3 and P4 connectors have an "A" row (A1 through A32) and a "C"
row (C1 through C32). All "A" row pins are the high side of the input signal. All "C"
row pins are the low side of the input signal. The preferred method of connecting
analog input signals is to connect both high and low inputs for each channel
(differential). Differential inputs provide for very high common mode noise
rejection by rejecting differences in ground potential between the analog
transmitter and the VMIVME-3112 Board. The board is factory configured to accept
differential inputs.
A second method of connecting analog inputs is called pseudodifferential. In this connection scheme only one ground reference is brought to the
board and connected to the P3 connector at pin C1. This implies that all connected
channels from the field must be referenced to the same ground. This method has
some of the advantages of differential inputs in that it helps reject ground
differences, but is not as good in common mode noise rejection. Jumper J1 must
be installed to enable this mode. In addition, the SIP resistors on the inputs must
be in the single-ended position as described in Section 5.4.3.1.
A third method of connecting analog inputs is single-ended inputs. This
method uses the on-board analog ground as the input signal reference. This is
generally the least accurate of the three methods. However, in a low noise
environment and when short cabling is used this method will work well. The input
sip resistors must be moved from the differential to single-ended sockets (refer to
5.4.3.1) and jumper J2 must be installed.
A Connector and I/O Cable Applications Guide (VMIC Document No.
825-000000-006) is available from VMIC that provides additional information
concerning field connections, the use of round cables, and a thorough explanation of
compatible connectors and cabling techniques.
