IC687BEM742使用方法,GE燃機(jī)模塊
由于七條線路用于解碼車載功能（第4節(jié)），VMIVME-3112板地址由八行地址位A08定義通過A15。電路板地址通過安裝短路插頭來編程“零”或低地址位跳線位置，并通過省略“一”或高位。地址位A06的權(quán)重為64字節(jié)位置。像例如，表5.4.2-1中所示的跳線布置將產(chǎn)生NNNN85XX十六進(jìn)制的板地址*輸入/輸出訪問模式通過正確選擇跳線AM2進(jìn)行編程條形圖（AM2上有一條線）和AM2。選擇短期非特權(quán)訪問安裝跳線AM2 bar（AM2上有一條線）。選擇短監(jiān)督訪問忽略兩個跳投。跳線AM2的安裝允許電路板響應(yīng)以下任一情況：訪問類型。
IC687BEM742使用方法5.4.3模擬輸入模式5.4.3.1差動或單端操作VMIVME-3112板出廠時配置了模擬輸入用于差動操作。模擬輸入模式由48個插座內(nèi)的32個電阻器SIP（標(biāo)記為RP1到RP 48）。如果VMIVME-3112保持部件側(cè)朝上，前面板朝左，然后，SIP套接字形成六列。最左邊的兩列應(yīng)始終安裝SIP。兩個中間立柱應(yīng)安裝SIP，以配置差分輸入。最右邊的兩列應(yīng)具有SIP安裝用于配置單端輸入。SIP是對稱的。不會的向后安裝會很痛苦。在單端模式下，外場接地感應(yīng)輸入可以用于補(bǔ)償設(shè)備信號之間的電位差返回。如果安裝了J1跨接導(dǎo)線，輸入接頭P3的針腳C1將用作所有單端輸入的接地感應(yīng)。板上有一個40.2 K電阻器VMIVME-3112將傾向于將該接地傳感器拉至VME總線數(shù)字接地。如果安裝了J2跨接導(dǎo)線（而不是J1），則單端輸入將工作相對于VME總線數(shù)字接地（可能非常嘈雜）。建議使用該電路板用于差分輸入模式。為了正確操作，任何輸入引腳上的電壓不得超過相對于VMEbus接地（+）或（-）12 V。隔離輸入源將具有不確定的共模相對于VMEbus接地的電壓。在這種情況下，可能需要為信號源提供VME接地參考。在差分模式下，通常沒有接地參考可在VMIVME-3112的P3或P4上使用。VME接地在VME上可用背板。獲取地面基準(zhǔn)的另一種方法是安裝跨接導(dǎo)線J1和J2。安裝J1和J2后，輸入通道0將不可用作差分輸入，但P3上的針腳C1將被連接至VMEbus接地。通道0仍可用作單端輸入。通過P3引腳C1的電流連續(xù)不得超過750 mA。
Since seven lines are used for decoding on-board functions (Section 4),
the VMIVME-3112 Board address is defined by eight lines, address bits A08
through A15.
The board address is programmed by installing shorting plugs at all
"zero" or LOW address bit jumper positions, and by omitting the shorting plugs at
the "one" or HIGH positions. Address bit A06 has a weight of 64 byte-locations. As
an example, the jumper arrangement shown in Table 5.4.2-1 would produce a
board address of NNNN85XX HEX.*
The I/O access mode is programmed by proper selection of jumpers AM2
bar (AM2 with a line over it) and AM2. To select short nonprivileged access install
jumper AM2 bar (AM2 with a line over it). To select short supervisory access omit
both jumpers. The installation of jumper AM2 allows the board to respond to either
type of access.
5.4.3 Analog Input Modes
5.4.3.1 Differential or Single-Ended Operation
The VMIVME-3112 Board is shipped with the analog inputs configured
for differential operation. The analog input mode is controlled by the positions of
32-resistor SIPs within 48 sockets (labeled RP1 through RP 48). If the
VMIVME-3112 is held with the component side up and the front panel facing left,
then the SIP sockets form six columns. The two left-most columns should always
have SIPs installed. The two middle columns should have SIPs installed to
configure differential inputs. The two right-most columns should have SIPs
installed to configure single-ended inputs. The SIPs are symmetrical. It will not
hurt to install them backwards.
In the single-ended mode, the external field ground sense input can be
used to compensate for the potential differences between equipment signal
returns. If the J1 jumper is installed, pin C1 of the input connector P3 serves as a
ground sense for all single-ended inputs. There is a 40.2 K resistor on board the
VMIVME-3112 which will tend to pull this ground sense to VME bus digital ground.
If the J2 jumper is installed (instead of J1) then the single-ended inputs will operate
relative to VME bus digital ground (which may be quite noisy). It is recommended
that the board be used in the differential input mode. FOR PROPER OPERATION, THE VOLTAGE ON ANY INPUT PIN MAY NOT EXCEED
(+) OR (-) 12 V RELATIVE TO THE VMEbus GROUND.
AN ISOLATED INPUT SOURCE WILL HAVE AN INDETERMINATE COMMON MODE
VOLTAGE RELATIVE TO VMEbus GROUND. IN SUCH CASES IT MAY BE NECESSARY TO
PROVIDE SIGNAL SOURCES WITH THE VME GROUND REFERENCE.
IN DIFFERENTIAL MODE THERE IS NORMALLY NO GROUND REFERENCE
AVAILABLE ON P3 OR P4 OF THE VMIVME-3112. VME GROUND IS AVAILABLE ON THE VME
BACKPLANE. AN ALTERNATE METHOD OF OBTAINING A GROUND REFERENCE IS TO
INSTALL JUMPERS J1 AND J2. WITH J1 AND J2 INSTALLED, INPUT CHANNEL 0 WOULD
NOT BE USABLE AS A DIFFERENTIAL INPUT BUT, PIN C1 ON P3 WOULD BE CONNECTED
TO VMEbus GROUND. CHANNEL 0 MAY STILL BE USED AS A SINGLE-ENDED INPUT.
CURRENT THROUGH PIN C1 ON P3 SHOULD NOT EXCEED 750 mA CONTINUOUS.
