ANSALDO VME-SSI?AVMESSI
輸入模塊的濾波可以降低輸入信號的線間的差模干擾。為了降低輸入信號與大地間的共模干擾，PLC控制器要良好接地。輸入端有感性負(fù)載時(shí)，對于交流輸入信號，可在負(fù)載兩端并接電容和電阻，對于直流輸入信號可并接續(xù)流二極管。為了抑制輸入信號線間的寄生電容、與其他線間的寄生電容或耦合所產(chǎn)生的感應(yīng)電動(dòng)勢，可采用RC浪涌吸收器。
輸出為交流感性負(fù)載，可在負(fù)載兩端并聯(lián)RC浪涌吸收器；若為直流負(fù)載，可并聯(lián)續(xù)流二極管，也要盡可能靠近負(fù)載。對于開關(guān)量輸出的場合，可以采用浪涌吸收器或晶閘管輸出模塊。另外，采用輸出點(diǎn)串接中間繼電器或光電耦合措施，可防止PLC控制器輸出點(diǎn)直接接入電氣控制回路，在電氣上完全隔離。
The second task is to identify all points in the loop that might be attached to earth ground. Devices like PLCs and power supplies frequently attach the connections to earth ground. Some sensors, like thermocouples, might not be electrically isolated and cause an unintended earth point.
Having more than one earth point in the loop will cause the loop to malfunction because current can flow between the earth points instead of through the wires.The third task is to pick the cable. There are many existing solutions supplied by cable manufacturers. We recommend a twisted pair cable of at least #22 AWG.The exact cable a particular installation will require will depend on the environment the cable is run through and the length of the cable. This document contains general advice and is not meant as a formal engineering solution to any particular application.
A 4/20mA signal can represent anything, but the values that the loop represents are always defined by the transmitter (or transducer) in the loop. The range of the transmitter identifies the values being transmitted at 4mA and at 20mA.Obtain the range of the transmitter and you will know what to set the display(s) to. Sometimes a transmitter sends a signal related to but not a direct measure of the desired quantity.
GEDS200SLCCG1AEE
GEIC660ELB912
GEIC660ELB912
GEIC660ELB912
GEDS200ADPBG1ABB
GE531X307LTBAJG1
GE531X307LTBAJG1
GE531X307LTBAHG1
GEDS6800CCIE1F1D
GE531X304IBDAMG1
GE531X304IBDAMG1
GE531X303MCPBBG1
GE531X303MCPBBG1
GER-TPD3
GESBI-PDP-32
GEVMIVME-7807
GEVMIVME-7807
GEVMIVME-7807
GE511-0101-08B
GEUR6CH
GEUR6CH
