Analog Channel Advanced Configuration

The Advanced Device Configuration section allows you to perform advanced tasks, including configuring analog channels. These settings apply in addition to those configured in the Transmission Interval and Stream Management sections.

Introduction to Analog Channel Advanced Configuration

An analog channel outputs continuous signals, making it ideal for measuring physical quantities like temperature, pH, and pressure. Advanced configuration tasks, such as applying data smoothing or setting up signal parameters, are done in the Device Advanced Configuration tree.

What is an Analog Sensor?

Analog sensors produce a continuous signal based on the measured quantity:

1. Current-Output Sensors (e.g., 4–20 mA):

   • Example: A pH sensor outputs 4 mA at pH 0 (most acidic) and 20 mA at pH 14 (most basic).

2. Voltage-Output Sensors (e.g., 0–5 V):

   • Example: A pH sensor outputs 0 V at pH 0 and 5 V at pH 14.

Accessing Advanced Settings for Analog Channels

1. Navigate to Devices in the left pane.

2. In the Sites Tree, select the device.

3. Click the Configuration tab in the right pane.

4. Locate the desired channel in the Stream Management Table and note its # column (channel number).

5. Scroll past the table and click Advanced Device Configuration.

6. Expand the Analog node in the configuration tree.

7. Expand the Channel node and select the channel number noted in Step 4.

8. Configure the parameters under the channel number node as described below.

9. Save changes and reboot the device:

   • Go to the Commands tab in the right pane and look for a Reboot command.

   • If no command appears, manually reboot by clicking Actions > Reboot in the Device Information pane.

Description of Analog Channel Parameters

1. Active

   • Description: Determines whether the channel is enabled, disabled, or on hold.

   • Options:

     • AS_ON: Channel is active and recording samples.

     • AS_OFF (default): Channel is inactive.

     • AS_ON_HOLD: Active but waiting for a trigger.

   • Note: For firmware 2.320 and newer, use the group’s AS_ON_HOLD parameter instead.

2. Channel Type

   • Description: Specifies the pin receiving signals and the data type (Voltage or Current).

   • Options:

     • CT_CURRENT_1 to CT_CURRENT_4 for current sensors (pins 1, 7, 6, 5).

     • CT_VOLTAGE_HIGH_1 to CT_VOLTAGE_HIGH_4 for voltage sensors (pins 1, 7, 6, 5).

   • Notes:

     • Pins 3 and 4 provide power, and pin 8 is GND.

3. Sample Power Source

   • Description: Specifies the sensor’s power supply.

   • Options:

     • PS_EXT1_BOOST or PS_EXT2_BOOST for 12V power (recommended for most sensors).

     • PS_EXT1 or PS_EXT2 for 3.6V power.

   • Note: For power requirements below 6V, contact support.

4. Filter Type

   • Description: Specifies how noise in the sensor signal is reduced.

   • Options:

     • FILTER_MEAN: Average value using mean.

     • FILTER_MEDIAN: Average value using median.

5. Wakeup Time (ms)

   • Description: Time, in milliseconds, for the sensor to stabilize before sampling begins.

6. Sample Interval (s)

   • Description: Time interval between samples.

   • Example: If set to 900 seconds, the sensor samples every 15 minutes.

7. Graph Normalizer Parameters

   • Description: Parameters (a, b, and c) to normalize sensor data.

   • Example: To convert 4–20 mA to 0–14 pH:

     • a = 7, b = 8, c = 3.

8. Group Priority

   • Description: Determines the sampling order for sensors in the same group.

9. Analog Input Lowpass Filter (Firmware 2.388 and newer)

   • Description: Reduces high-frequency noise in the signal.

   • Options:

     • ILF_BYPASS: No filtering.

     • ILF_RC: Low-pass filter using a resistor-capacitor circuit.

     • ILF_DECAP: Removes high-frequency noise using a decoupling capacitor.

Smoothing Data (Optional)

Raw data smoothing can be done in three stages:

1. Moving Average: Smooths short-term fluctuations.

2. Graph Normalizer: Adjusts data points using a scaling formula.

3. Final Moving Average: Further refines the data.