In general, a valid license code is necessary for operating an RM4200D. There are license codes for the operation of the software itself and additional codes for enabling the Enhanced DSP Functions. The latter license codes enable optional processing functions and must be ordered separately (product code RM420-561).

A license code is always stored in the Communication&Logic Controller RM420-850. Each RM420-850 module has its own license code basing on the last 3 bytes of the Ethernet MAC address of the module. You can check whether a module RM420-850 is already licensed or not, using the maintenance window. Simply mark the module and press F11 to read out the module information.

	Important
	If you exchange an RM420-850 module, you may need a new license code that you can order from your DHD dealer. When ordering, please indicate the last three bytes of the Ethernet MAC address. Using the command Show module information (functional key F11) will show you the address of the module; the value is displayed in the line MAC address (e.g. 0100ce).

You can find more detailed information about license codes and how to enter license codes in the configuration guide. This part of the RM4200D manual can be found on the website as well as on the CD included in the shipment (See manual Part 3 - Chapter 3. Maintenance Window - Maintaining the modules / Device-Menü).

In most cases, DHD delivers the mixers with a time-limited license code (marked valid until..., (See figure 1–35.) As soon as the system has fully passed into the property of the customer, DHD sends an e-mail with a permanent license code.

Figure 37: Module information of an RM420-850 with time limited license code (selection)

After entering a valid license code, the module information changes (See figure 1–36.).

Figure 38: Module information of an RM420-850 permanent license (selection).

	Note
	If you have not received any license code for your RM4200D system, please contact your DHD dealer immediately.

In tender and invoice correspondence, DHD informs its clients that a license is necessary for the use of each RM4200D. Both documents include the following passage: The devices are delivered with a time-limited license key. After full payment, the customer receives a time-unlimited license key.

Important

An RM4200D system without a valid license code allows the unrestricted operation (except Enhanced DSP Processing) for a duration of 600 hours, which corresponds to 25 days non-stop operation. After that, a "License invalid" message appears in the Rotary Encoder Displays of the Control Modules (RM420-010, RM420-012, RM420-013, ...). Except for this message and the Enhanced DSP Processing, operating the system is still possible without restrictions. After 800 hours of operation without a valid license, the system causes about one reset per hour. The Enhanced DSP functions are inactive when an invalid license code is used; signals in the DSP are only bypassed (bypass mode).