PQM-T20-C-A輸入模塊,GE使用產品PQM-T20-C-A
降額曲線：ALG392為了獲得最大性能和模塊壽命，模塊應在最大負載電阻下運行卸載熱量。模塊熱降額取決于電壓水平以及電流和電壓的使用輸出。以下前兩個圖表顯示了僅限電流模塊的最高周圍空氣溫度在30 VDC和26.5 VDC下。混合電流和電壓輸出在下面所示的示例中，電壓通道具有2千歐負載，電流通道具有短路負載。
PQM-T20-C-A輸入模塊要確定混合電流和電壓輸出的最大工作溫度，請選擇對應于所用電壓通道數量的下表。例如，一個模塊使用2電壓通道和3個電流通道。總通道數為5，最高工作溫度約52.5°C：電流和電壓范圍和分辨率在4到20mA范圍內，模塊掃描PLC的輸出數據，使4mA對應于0的計數，20mA對應32000計數。在0到20mA的范圍內，用戶數據被縮放為0 mA對應于0的計數，20mA對應于32000。在0到20mA模式下，最大值為32767提供約20.5mA的最大輸出。在當前模式下，模塊還報告開環PLC故障。對于默認單極模式（0至+10伏）下的電壓操作，對數據進行縮放，使0伏對應0和+10伏的計數對應32000的計數。在此模式下，高達32767的值將創建一個過量程輸出約為10.24伏。在-10至+10伏范圍內，數據按比例縮放，使-10伏對應于-32000和+10伏的計數對應于+32000的計數。在此范圍內，從-32767到+32767的輸出值會導致超范圍大約-10.24伏到+10.24伏。電流和電壓范圍的比例如下所示。
Derating Curves: ALG392
For maximum performance and module life, the module should be operated at maximum load resistance to
offload heat. Module thermal deratings depend on the voltage level and the use of current and voltage
outputs. The first two charts below show the maximum surrounding air temperature for current-only modules
at 30 VDC and at 26.5 VDC.Mixed Current and Voltage Outputs
In the example shown below, voltage channels have 2 KOhm loads and current channels have shorted loads.
To determine the maximum operating temperature for mixed current and voltage outputs, select the line in the
chart below that corresponds to the number of voltage channels being used. For example, a module uses 2
voltage channels and 3 current channels. The total channels are 5, and the maximum operating temperature
is approximately 52.5°C:Current and Voltage Ranges and Resolution
In the 4 to 20mA range, the module scans output data from the PLC so that 4mA corresponds to a count of 0,
and 20mA corresponds to a count of 32000. In the 0 to 20mA range, user data is scaled so that 0 mA
corresponds to a count of 0 and 20mA corresponds to 32000. In 0 to 20mA mode, a value up to 32767
provides a maximum output of approximately 20.5mA. In current mode, the module also reports an open loop
fault to the PLC.
For voltage operation in the default unipolar mode (0 to +10 volts), data is scaled so that 0 volts corresponds
to a count of 0 and +10 volts corresponds to a count of 32000. In this mode, a value up to 32767 creates an
overrange output of approximately 10.24 volts.
In the -10 to +10 volt range, data is scaled so that -10 volts corresponds to a count of -32000 and +10 volts
corresponds to a count of +32000. In this range, output values from -32767 to +32767 result in an overrange
of approximately -10.24 volts to +10.24 volts.
Scaling for both current and voltage ranges is shown below.
