HelixNet version 4.1 and onward allows a HMS-4X in any linking mode (Disabled, Link Master or Link Member) to be swapped for an identically configured cold standby unit which can be swapped in - one unit connected to the system at a time - without additional user interaction (such as pairing or role selection of endpoints).
Primary HMS-4X; The unit normally used to run the HelixNet system
Cold-Standby HMS-4X; The unit that is offline or powered down with an identical configuration to the powered unit. This unit is never running or connected to the system unless its Primary HMS-4X is powered down or disconnected from the system.
To prepare a Cold-Standby HMS-4X;
Setup and fully configure the HelixNet system
Store the configuration of the HMS-4X you would like to have a Cold-Standby unit from the FRONT PANEL USB connector on the Primary HMS-4X
Ensure the Cold-Standby HMS-4X is populated with identical HLI modules as the primary unit
Ensure the Cold-Standby HMS-4X is disconnected from any data and audio connections
Reset the Cold-Standby HMS-4X to default
Recall the stored file from the Primary HMS-4X using the FRONT PANEL USB connector on the Cold-Standby HMS-4X
Verify that the Network Settings and Host Name are recalled on the Cold-Standby HMS-4X and identical to the Primary HMS-4X
To change-over to a Cold-Standby HMS-4X;
Power down or physically disconnect the Primary HMS-4X from the system
Power up or physically connect the Cold-Standby HMS-4X to the system
Move all physical connections from the Primary HMS-4X to the Cold-Standby HMS-4X
Allow the Cold-Standby HMS-4X to boot-up or connect to the system
The Cold-Standby HMS-4X unit will connect to the Link Group following that all endpoints will connect and load their roles/keys.
Talk Keys will come up unlatched
Channel listen levels will be reset to unity gain
DO NOT allow the Primary and Cold-Standby HMS-4X to be online and connected at the same time! The units are on identical IP addresses and mDNS Host Names which will cause issues.
If the endpoints do not immediately start to connect to a Cold-Standby HMS-4X (was previously powered on but disconnected from the network) you may need to power-cycle the Cold-Standby HMS-4X to force the network to refresh. Remember that a HMS-4X power-cycle can be initiated by pressing HSET at the same time as the MAIN and PGM.
If the Cold-Standby HMS-4X is for a Link Master the Cold-Standby unit should be maintained by recalling its settings following changes to the Link Master.