This article illustrates how to set up a command and an interlock with PlantModel library.
Setting up a command
In order to set up a command with PlantModel library in Elipse E3, follow the steps below:
1. Firstly, find the object to which you want to add the command. Then, add a command folder com PlantModel library, as seen below:
2. After that, add and name the command units from inside the folder, as in the example below:
3. Finally, add the units (that is, the types of command it can issue) from inside the command, as in the figure below:
4. Property settings in the command unit:
- WriteTag: I/O tag that will receive the command;
- WriteValue: value sent to this command tag;
- Optionally: to write bits instead of values/words, you can set up UseDirectBit property as TRUE to enable bit write, and DirectBit property as the bit to receive the value in WriteValue.
Setting up an interlock
Always add the interlock right below the object you wish to interlock/block; therefore, to interlock/not allow a command to turn on a device that has already been turned on, you can add an interlock right below this command, in order to monitor this device’s status. If it’s turned on, you can block the command.
With this information, we can set up the interlock as seen below:
1. Firstly, we will add the interlock folder right below the command we wish to interlock; in this example, we’ll use the turn on command:
2. Then, add an interlock inside the interlocks folder, as in the example below:
3. After that, we’ll set up the interlock to block turning on the device when it’s already on. To do so, set up the properties as in the figure below:
Note: The ComparisonOperator property informs how Value and ComparisonValue compare to each other. Possible values are:
0 – Equal ; 1 – Different ; 2 – Less than ; 3 – More than ; 4 – Equal or less than ; 5 – Equal or more than.
4. In order to compare ComparisonValue and Value, we’ll retrieve the device’s value by association with Value property, as seen below:
