meter-board is our reference solution for measuring energy consumptions. This device provides seven inputs for current sensors and three inputs for electric/water/gas meters capable to provide electric pulses. Meter-board acts as any other wireless device in the panStamp ecosystem; it can be configured and read wirelessly from any node or computer connected to a panStick.
Figure 1 : panStamp meter-board
Current sensors need to be clamped to one of the AC wires. Depending on the readings provided by the device, you will maybe need to switch to the other wire in order to match the correct phase. Phase mismatches typically produce very low power factor readings.
Figure 2 : Wire connections
Once meter-board is correctly wired, it's time to configure each of the inputs. Firstly, disabling unused inputs is a good practice since this will release the device from having to do useless measurements and transmissions. Then, we need to enter the correct calibration settings for the inputs and choose the units for the pulse counters. All this configuration process can be done from SWAPdmt, our configuration tool. In order to open the configuration menu for each of the inputs we need to right-click “Config parameter X” and then select “custom settings”
Figure 3 : AC current sensor – Config settings
Each current sensor has an associated scaling factor. This factor is used to convert ADC readings to true AC current values. The following are some calibration values for different current transformers:
SCT-013-005 --> 5
SCT-013-030 --> 30
We also need to enter the scaling factor for the voltage transformer. The board has a unique voltage transformer but we need to enter this scaling factor for every current sensor input. Voltage transformers supplied by panStamp have a scaling factor of 1745, being this the factory default for the AC current inputs.
Figure 4 : Pulse input – Config settings
Pulse inputs have different configuration parameters. Initial value has to be filled with the reading appearing in the meter display. This value will be taken as a starting point where to count consumptions from. “Counts per unit step” is the amount of steps to be counted before increasing the reading one unit.
meter-board periodically transmits energy consumptions measured from the AC channels. The transmission interval can be configured from SWAMdmt (network settings). Meter-board provides the following informations for each AC channel:
Figure 5 : AC readings from SWAPdmt