How to adjust an output voltage

DC voltages are commonly used as control signals for various industrial equipment and machinery. The Analog Output Module can be used to generate these voltages which can be controlled by a PC or Laptop. ModCom provides a few Screen Objects which are ideal for communicating with this module and setting the voltages on each of its output channels. An Input Window can be used to change the voltage on the fly by typing in a number via a keypad that pops up on the screen. A Rocker Switch or a Slider Control can be used to scroll the voltage up and down with the mouse. Simply choose one of these objects from the <Place Object> menu at the top of the screen and move it to the desired position using the mouse. Follow the steps below to set up the object for operation.

Using an Input Window:

Step 1: To set the properties of the Input Window, right-click on the object. This will bring up the Properties dialog box which contains a number of user defined attributes which can be used to customize the Input Window's appearance and operation.

Step 2: In the "Execute this Function" section at the bottom of the dialog box, choose "Transmit Command" and type in the command string from the command set shown in Table 2 of the product data sheet which is required to set the voltage on an output channel. Replace the "value" portion of this command string with the object ID label of this Input Window enclosed in curly braces like this {InputWindow1}. For example, to set it up to control the voltage on channel A of module A, type in the following command string: AVA{InputWindow1}

Step 3: Close out the dialog box and start the main run-time loop by clicking on the green "Run" button at the top of the screen. Once in run mode, clicking on the "Edit" button will bring up a keypad that will allow you to key in the voltage desired of the Analog Output Module.

Using a Rocker Switch:

Step 1: To set the properties of the Rocker Switch, right-click on the object. This will bring up the Properties dialog box which contains a number of user defined attributes which can be used to customize the Rocker Switch's appearance and operation.

Step 2: In the box labeled "Start with this value", type in the initial voltage level that you wish the analog output channel to be set to when starting the run-loop.

Step 3: Unless you have manually disabled the Echo feature of the Analog Output Module, check the box labeled "Response expected from Module" in the Communications section.

Step 4: In the "Value Limit" box of the "Press Up Function" section, enter the upper voltage limit of the analog output. In the box directly below this, type in the command string from the command set shown in Table 2 of the product data sheet which is required to set the voltage on an output channel. Omit the "value" portion of this command string because it will be taken from the value entered in step 2.

Step 5: In the "Value Limit" box of the "Press Down Function" section, enter the lower voltage limit of the analog output. Make sure that the starting value entered in step 2 falls within the range of the upper and lower limits entered here and in the previous step. In the box directly below this, type in the same command string which was entered in step 4.

Step 6: Close out the dialog box and start the main run-time loop by clicking on the green "Run" button at the top of the screen. Use the left mouse button to hold down the top or bottom of the Rocker Switch and watch how the voltage of the Analog Output Module scrolls up and down in response.

Using a Slider Control:

Step 1: To set the properties of the Slider Control, right-click on the object. This will bring up the Properties dialog box which contains a number of user defined attributes which can be used to customize the Slider Control's appearance and operation.

Step 2: In the box labeled "Start with this value", type in the initial voltage level that you wish the analog output channel to be set to when starting the run-loop.

Step 3: Unless you have manually disabled the Echo feature of the Analog Output Module, check the box labeled "Response expected from Module" in the Communications section.

Step 4: In the "Slider Configuration" section, enter in the desired top and bottom values of the Slider Control range. Make sure that the starting value entered in step 2 falls within this range. In the box directly below this, type in the command string from the command set shown in Table 2 of the product data sheet which is required to set the voltage on an output channel. Omit the "value" portion of this command string because it will be taken from the value entered in step 2.

Step 5: Close out the dialog box and start the main run-time loop by clicking on the green "Run" button at the top of the screen. Use the left mouse button to drag the Slider Control's knob up and down and watch how the voltage of the Analog Output Module slides up and down in response.