When Tidel launched the Sentinel Control Module (SCM) cash management system in 2012, it introduced several new innovations in smart safe technology. One such innovation was the note validator maintenance door, which is also offered on the system that replaced the SCM – the Tidel Series 4, our current flagship product.

In this article, we’ll discuss the reasons why we introduced this innovative feature, and the benefits it provides our customers.

Maximizing System Uptime

Before the introduction of the note validator maintenance door, it was our experience that approximately 70-80% of service calls were related to note jams. Most of the time, this failure had nothing to do with the validator itself. Rather, the jam was simply due to a user unknowingly depositing a bad note into the system. A bad note might be caused by excessive wear and tear, dirt or dust, or foreign objects. In a busy retail environment, these factors can be difficult to detect.

With many of today’s smart safe designs, accessing the note validators also means accessing the note cassettes, since both are accessible via the same door. Since the note cassettes store the deposited funds, this vault door will likely have restricted access – usually to just the armored car provider, or service technician. In this case, if a note jam occurs, the store will have to request a service technician to arrive at the store, access the system, and clear the jam. This can effectively take the safe out of commission for hours, even days – impacting store operations and security – all for a service call that takes under a minute to complete.

With the introduction of the note validator maintenance door, this issue goes away. With the maintenance door, pre-authorized store personnel (with the appropriate log in credentials) can open the door, remove the note validator, clear the jam, and replace the validator in under a minute’s time. This activity can happen without taking the safe offline.

This innovation has had a dramatic effect on overall system uptime and reliability, from which our customers have greatly benefitted.

Protecting the Integrity of the Funds

With the SCM and Series 4, each system was designed in such a way that, even with the note validator maintenance door opened, a user cannot access the funds in the cassettes. This is critically important to ensure the security and integrity of deposited funds. Each door can be set with its own access levels, which is completely customizable via the system console.

Performing Routine Maintenance

To ensure maximum performance of the note validator, a user may need to perform regular routine maintenance. This could involve cleaning of the inside of the validator, using approved instruments and solvents. In this instance, the removal of the validator would be required. This is yet another reason why the introduction of the note validator maintenance door has been so well-received by our customers, as they can perform this maintenance themselves, versus having to hire a technician to perform this service.


Since their inception, smart safes have gone through several cycles of innovation. Some of these have been driven by technology, some by the user experience, and others out of simple necessity. At Tidel, we feel the introduction of the note validator maintenance door addresses the latter two drivers. The note validator maintenance door, in our view, is a necessary feature that has helped to dramatically reduce system downtime, maintain overall security, and greatly improve the customer experience.

If you would like more information on this innovative feature, or our smart safe portfolio in general, please email [email protected] or call 1-800-678-7577.