In the Roker Enforcement web app (back-end), log in and head over to Settings > Location. Click the Edit button on the location you'd like to add Tire Chalking to. 

Expand the Advanced setting and you'll see the image below. 

Reset Plate Option: this is the length of time or the daily time after the plate was first scanned for that plate to be allowed to be scanned again. Options are: 

Hit Save.

Login to the mobile app

Ensure you're using the most recent version of the mobile app (you can check by searching Roker Patrol on the Google Play Store; if there is an update available, down and install). If you made any changes to the Location Settings in step 1 and you're still logged in, log out and back into the app to apply those changes

Select Your Location

From the dropdown list, select your location. At this point you have two options; launch the scanner to start enforcing with LPR, or manually enforcing. To manually enforce, go onto step 4. To enforce using LPR, skip to step 5. 

Manually Enforce

In the search bar at the top, enter in the license plate number. There may be 2 scenarios: 

1. A blue, green, yellow or red pops up with the plate info: this means there is currently an active session and there is no need to create a chalking session. 
2. A box with a "Submit Digital Chalking" button pops up.
   

If you're prompted to submit a digital chalking, go ahead and do so. There are two outcomes; if the plate has not been previously chalking within the reset time, you'll be left on the location results screen and can continue to enforce. If you are taken to the License Plate Details screen and there is no data for that location under the Permit Parking or Active Parking Sessions boxes, this plate was previously chalked, is still within the reset time and can be issued a violation.

Enforce Using LPR

Click the Launch Scanner button. This will open the built-in LPR software and you can begin scanning plates immediately. If a plate scans and you see a "Digital Chalking Created" popup, this means that the plate has not been previously chalking within the reset time, and has created a session.

If you scan a plate and are taken to the Plate Details Screen, and there are no other active sessions or permits for that plate and location, this means the plate was previously scanned within the reset time and you can then issue a violation or ticket. 

If a plate has an active session whether that is a paid session, an active permit or if they still have an active tire chalking session, you will see "Plate Whitelisted" at the top of the screen and will remain on the scanner to continue to scan. No actions will need to be taken at that point. 

Editing a misread plate: all plates read by LPR open to a confirmation screen. You can hit the green checkbox if it's correct, or edit the plate directly by clicking on the plate characters then hitting the green checkbox when correct.

When in Offline mode, Roker Patrol also cannot update the active parking sessions list, so note that the longer you're offline, the more chances you may be missing some active sessions being created.