CR1000XMeasurement and Control Datalogger

Expand AllCollapse All

1. Why are single-ended measurements used in theACPower()instruction in CRBasic when the outputs of the potential transformer and current transformer are inherently differential?

   电压互感器和电流转移mer provide differential outputs that have galvanic isolation from the voltage and current in the circuit they are measuring. However, there is no need to run the outputs of these transformers into differential inputs of the data logger and unnecessarily consume additional data logger channels. We conducted extensive testing for noise immunity, for inaccuracies from ground loops, and more before concluding that single-ended measurements in theACPower()instruction have the same performance as differential measurements would provide. Please note that as a result of the galvanic isolation of the potential transformer and current transformer, the data logger ground is NOT connected to the ground of the circuit they are measuring.

   Said differently, you can connect differential outputs of a sensor to single-ended inputs of the data logger. However, doing so creates the possibility of poor common-mode noise rejection in the data logger and the possibility of introducing inaccuracies from ground loops between the sensor and the data logger. Note that in this application, the transformer isolation of the potential transformer and the current transformer eliminates these concerns.

   Simply connect one of the potential transformer secondary wires and one of the current transformer secondary wires to the data logger ground. Which wire in either case makes a difference, as the phase information allows the measurement of power flowing in either direction. If you measure negative real power when it should be positive, then reverse the secondary wires of the potential transformer where they connect to the data logger. Alternatively, you can reverse the secondary wires on the current transformer, but don't reverse both pairs of wires.

2. IF PC208W is running on Windows XP, can it be set up to communicate with a CR1000X?

   The CR1000X is not compatible with PC208W.

3. In the event that the CR1000X becomes damaged and needs a new wiring panel, what should be done?

   将CR1000X退还给Campbell Scientific进行维修。有关获得退货材料授权（RMA）的协助，请遵循有关的指示Repair and Calibration page。

4. CR1000X是否具有类似于CR6的Thermistor（）指令？

   No.

5. How does the power usage of the CR1000X compare to the power usage of the CR1000 or CR6?

   When idle, the CR1000, CR6, and CR1000X consume less than 1 mA @ 12Vdc. Similar to the CR6, the CR1000X has a much faster processor that requires more power when up and running. As such, there will be higher current draws during active measurements, serial communications, or when plugged into a PC via USB or Ethernet.

   将CR6和CR1000X视为建立在同一“平台”上可能会有所帮助。

6. After the release of the CR1000X, will the CR1000 continue to be sold and supported?

   The CR1000 and CR1000X will be sold concurrently for no less than two years. We anticipate the CR1000 will be retired in December of 2019 and will be supported until December of 2029.

7. 可以在CR1000X上使用为CR1000编写的程序吗？

   Although there are significant additions to the CR1000X program instructions that are not available in the CR1000, in most cases, you can load your program written for the CR1000 to a CR1000X with minor instruction changes. The most notable of the minor instruction changes is in the analog measurement instructions. For more information, see the"Replacing Your CR1000 Data Logger with a CR1000X: What You Should Know" blog article。

8. If a CPI-enabled device is running and there are skipped scans in the data logger, what can be done?

   The default CPI bus speed setting is 250 kB/s. The speed is adjustable in your CRBasic data logger program. Use theCPISpeed()instruction in your CRBasic program to adjust the CPI bus bandwidth to meet the following maximum combined (total) Ethernet cable lengths:

   • 1000 kB/s for maximum combined Ethernet cable lengths of 15.2 m (50.0 ft)
   • 500 kB/s for maximum combined Ethernet cable lengths of 61.0 m (200.0 ft)
   • 250 kB/s for maximum combined Ethernet cable lengths of 152.4 m (500.0 ft)