To assign and separate trailers, the following access rights are required:

• Create, edit, and delete trailers. To the resource that contains the trailers.
• View object and its basic properties. To the units that should be used when assigning and separating the trailers manually.
• Use unit in jobs, notifications, routes, retranslators. To the units that should be used when assigning and separating the trailers automatically.

Trailers can be assigned to units manually or automatically. After that, you can work with the assignment history. 

In some cases, several trailers can be assigned to the same unit simultaneously. Read about simultaneous assignments and how to avoid them here.

Manual assignment and separation

To assign a trailer to a unit manually, follow the steps below.

1. Click on the icon  opposite the required trailer in the list of trailers or their groups. If you don't have the Create, edit, and delete trailers access right to the resource, the icon is inactive ().
   
2. In the open window, select the unit to which you want to assign the trailer. Here you can see the units from the work list on the Monitoring tab. If no units are displayed, click on the icon  to the left of the search. If still no units are displayed, it means you don't have the View object and its basic properties access right to them.
3. Click OK.
   

After that, the icon of the selected unit is shown in the trailer row.

To separate the trailer from the unit, point to the unit icon in the trailer row and click on the icon . 

You can also separate the trailer by registering a new shift for it or by deleting its assignment (see more).

Automatic assignment and separation

Automatic assignment and separation of trailers requires special equipment, for example, the iButton electronic keys.

For all the units, to which you want trailers to be assigned automatically, create a sensor of the Trailer assignment type. You can create it in the same way as a sensor of the Driver assignment type. Next, follow the steps below.

1. On the Trailers tab, click on the icon .
   
2. In the list of resources, select the resource for the trailers of which you want to configure automatic assignment. To find out which trailers belong to a certain resource, apply filtering by resource to the trailer list (displayed to the right of the New button).
3. Click Next.
   
   
4. Select the units or unit groups to which the trailers of the selected resource should be assigned automatically. To switch between the lists of units and their groups, use the icon /. For more information about the unit selection, see Creating jobs.
5. Click ОК.
   

The automatic separation of trailers is carried out:

• after receiving the parameter with the separation code specified in the properties of the Trailer assignment sensor;
• after receiving the parameter with an empty value;
• as a result of the notification with the Separate trailer action (for example, when turning the ignition off);
• after assigning another trailer to the unit, provided that the Exclusive option is enabled in the new trailer properties (see more).

To disable the automatic assignment and separation of trailers, click on the icon , select the resource, clear the selection of the required units and save the changes.

Working with assignment history

To view the assignment history of the trailer and register its shifts, you should have the Request reports and messages access right to the resource.

The Assignment history feature allows you to view the history of assignments, add records of assignments manually (register work shifts) and delete them if necessary. To perform these actions, click on the icon to the right of the trailer name.

To view the assignment history, specify the required interval and click Show. In the list of assignments, you can see the name of the unit, the date and time of the trailer assignment and separation from it.

You can delete an incorrect assignment or separation by clicking on the icon  at the end of the row. If an assignment is deleted from the history, it is not shown in reports either.

Registering shifts

To create a record of the trailer assignment in the past, follow the steps below.

1. Click Register shift. 
2. Select a unit in the drop-down list. 

3. Specify the time of the shift beginning and/or end. To enable the Shift end field, put a check mark near it.
   

   The date and time indicated as the shift beginning and end should be in the past or present. If you specify the beginning and end in the future, the shift is registered with the current date and time.

4. Click OK.