Configuring analog control loops - Verasys - LIT-12013364 - LC-VAC1000-0 - Smart equipment controller - VAC1000 - 4.2

Verasys Sideloop Controller Application Note

Brand
Verasys
Product name
VAC1000
Document type
Application Note
Document number
LIT-12013364
Version
4.2
Revision date
2021-07-16
Product status
Active
Language
English

You can configure the analog control loop strategy as a reset span, PID control, PID control with reset, or binary to analog. Different options appear depending on the configuration chosen.

To configure the control loop, complete the following steps:

Note: For analog control loop 1, the output goes to analog output 1, and so on. You can select the input for the control loop.
  1. Enable the unit: Details > System Configuration > General > Unit Enable.
  2. Enable the control loop: Details > System Configuration > General > Analog Control Loop x Enable.
  3. Select the control loop strategy: Details > Analog Control Loop x > General > Analog Output Control Selector.
  4. Enable binary interlock, if required: Details > Analog Control Loop x > General > Binary Interlock Enable.
    Note: If you enable binary interlock, then the corresponding binary input must have a closed circuit in order for the analog loop to start changing value.
  5. Configure the selected control loop strategy. For more information, see the relevant section:
  6. Configure the interlock strategy, if required. For more information, see Configuring analog control loop interlock.

Configuring the reset span strategy for analog control loops

The reset span strategy spans an input range and provides the corresponding output value in the output range. You can define both the input range and the output range.

Figure 1. Reset span strategy example

To configure the strategy, complete the following steps:

  1. Navigate to Details > Analog Control Loop x > Simple Reset.
  2. Select one of the following inputs types: SAB sensor, wired Analog Input (AI) sensor, or network shared sensor.
  3. Configure the span input low limit and high limit, and the corresponding span output low limit and high limit.

For the full list of parameters and their details, see Table 22.

Configuring the PID control strategy for analog control loops

The PID control strategy uses PID tuning to control an output process variable to a network setpoint. You can define both the process variable, for example, ZN-T, and the network setpoint value.

Figure 2. PID control strategy example

To configure the strategy, complete the following steps:

  1. Navigate to Details > Analog Control Loop x > Remote Setpoint FB Control.
  2. Select one of the following inputs types: SAB sensor, wired AI sensor, or network shared sensor.
  3. Configure the network setpoint, PID type, and tuning type.
  4. Configure the PID manual or automatic tuning parameters. Automatic tuning uses a number of predefined settings depending on the type of process being controlled.

For the full list of parameters and their details, see Table 23.

Configuring the PID control with reset strategy for analog control loops

The PID control with reset strategy sets a network setpoint and uses PID tuning to control an output process variable to that setpoint. To set the network setpoint, the strategy uses an input range, and provides the corresponding output value in the output range. You can define the input range, output range, the process variable, for example, ZN-T, and you can select the setpoint that the strategy resets based on the input.

Figure 3. PID control with reset strategy example
  1. Navigate to Details > Analog Control Loop x > Setpoint Reset from Input FB Control.
  2. Select one of the following inputs: SAB based sensor, wired AI sensor, or network shared sensor for process variable and setpoint.
  3. Configure the span input low limit and high limit, and the corresponding span output low limit and high limit.
  4. Configure the PID type and tuning type.
  5. Configure the PID manual or automatic tuning parameters. Automatic tuning uses a number of predefined settings depending on the type of process being controlled.

For the full list of parameters and their details, see Table 24.

Configuring the binary to analog strategy for analog control loops

The binary to analog strategy provides an analog output value based on the state of a binary input. You can define a binary input state to compare the actual binary input state to. You can define different output values for the case when the binary output matches your defined state and when it does not match the defined state. For example, if an occupancy sensor detects occupancy, you can turn on an exhaust fan at 60%. If occupancy is no longer detected, you can set the exhaust fan to 0%.

  1. Navigate to Details > Analog Control Loop x > Binary to Analog.
  2. Select the binary input.
  3. Configure the binary input setpoint to use in the comparison, and the analog output values for the match and the mismatch conditions.

For the full list of parameters and their details, see Table 25.

Configuring analog control loop interlock

  1. Navigate to Details > Analog Control Loop x > Binary Interlock.
  2. Configure the interlock mode, select a binary input, and configure the delay type and the delay times.
    Note: If the interlock is in control mode, the control loop works according to the state of the selected binary input. State 1 activates the control loop and state 0 disables the control loop and sets the output to 0%.

For the full list of parameters and their details, see Table 26.