3BHE014070R0101控制器卡件,3BHE014070R0101使用进展
四个通道中每个通道的转换速度为半毫秒。这提供了一个任何通道的两毫秒更新率。转换信号的分辨率为12位任意范围内的二进制（4096中的1部分）。%AI寄存器中的用户数据为16位2补码格式。将A/D转换器的12位放入%AI数据中文字如下所示。电流输入和A/D数据之间的关系转换器如图3-14和3-15所示。如果电流源反向输入，或小于电流范围的低端，然后，模块将输出与电流范围低端对应的数据字（0000H，单位：AI）。
3BHE014070R0101控制器卡件如果输入的输入超出范围（即大于20 mA），则A/D转换器将输出至满标度（对应于7FF8H，单位为%AI）。输入比例如下图所示。模块的输入保护足以保证在性能降低的情况下运行高达200V共模。该模块提供外部电气隔离通过使用光学隔离在现场布线和背板之间产生噪声。为了将电容性负载和噪声降至最低，模块的所有现场连接应使用优质绞合屏蔽仪表电缆接线。防护罩可以是连接到COM或GND。COM连接提供对模块中的模拟电路。接地连接提供对基板（框架）的访问接地）。当模块的电源工作时，面板顶部的LED亮起。主要模块的电源是由PLC电源提供的隔离+24 VDC电源。该电压通过逆变器/调节器传输，为模块提供工作电压。该模块还消耗PLC电源+5 VDC输出的电力，以驱动隔离电路。该模块可以安装在90-30系列PLC系统。见第3-11页，以确定模拟电流输入的数量可安装在系统中的模块。
Conversion speed for each of the four channels is one-half millisecond. This provides an
update rate of two milliseconds for any channel. Resolution of the converted signal is 12 bits
binary (1 part in 4096) over either range. User data in the %AI registers is in 16-bit 2’s
complement format. The placement of the 12 bits from the A/D converter in the %AI data
word is shown below. The relationship between the current input and the data from the A/D
converter is shown in Figures 3-14 and 3-15.If the current source is reversed into the input, or is less than the low end of the current range,
then the module will output a data word corresponding to the low end of the current range
(0000H in %AI). If an input that is out of range is entered (that is, it is greater than 20 mA), the
A/D converter will output up to full scale (corresponding to 7FF8H in %AI).
Input scaling is shown in the next figureInput protection for the module is sufficient to guarantee operation with reduced performance
with up to 200V common-mode. The module provides electrical isolation of externally
generated noise between field wiring and the backplane through the use of optical isolation.
To minimize the capacitive loading and noise, all field connections to the module should be
wired using a good grade of twisted, shielded instrumentation cable. The shields can be
connected to either COM or GND. The COM connection provides access to the common of the
analog circuitry in the module. The GND connection provides access to the baseplate (frame
ground).
An LED at the top of the faceplate is ON when the module’s power supply is operating. The main
power source for the module is the isolated +24 VDC power supplied by the PLC power supply.
This voltage is routed through an inverter/regulator to provide the operating voltage for the module.
