Desktop application for label scanning

PROBLEM: We need to scan labels into our application in Knack and also perform several checks when scanning the label. Unfortunately, doing it through a web interface introduces too much latency. SOLUTION: Create a local solution either with Excel or MS Access using the runtime library. We prefer the latter. This solution should download the necessary databases locally and perform checks locally. DETAILED REQUIREMENTS We use a web application called Knack to track our outbound packages and shipment data. JSON API calls must be made to this application to put or get data. Data should be pushed back to the application with each label scan. When the application executes an action, the latency between executing the action on the client side and being ready for the next scan must be 0.1s or less. Pushing the data back to the main application may take longer, so a queueing mechanism of some sort may be necessary. Interface requirements: Application should be easy to use. No intervention from the user should be required to perform application functions such as getting remote resources, or pushing data back to the web database. We need to perform the following checks when scanning a label. These checks must be reliable against both the existing database and any queued data. 1. Reject duplicate label numbers 2. Reject different label numbers for the same order 3. Reject labels from orders that have been flagged 4. Reject labels with no associated shipment We use the following tables in our current web application: 1. Shipment records, which have both the order number and the tracking number fields 2. Scan records, which contain label number and scan time fields 3. Flag table, which contains the order number for orders that should be rejected We should also track errors, and push them to our existing web application in a new table.