Désolé de jouer les trouble-fêtes, mais une recherche sur le EX2100 Simplex de GE indique qu'il est question de "Warm Backup".

EX2100 Static Excitation System
... is only used in the simplex mode. Each board contains two ... one power conversion module, the GE EX2100 excitation system Warm Backup op- tion is available. ...

--------------------------------------------------
Note added at 59 minutes (2008-10-15 16:20:15 GMT)
--------------------------------------------------

http://www.geindustrial.com/products/brochures/GEA-S1028.pdf

http://www.gepower.com/prod_serv/products/oc/en/downloads/42...
In the warm backup and multibridge configurations, the EX2100 features redundant exciter control with triple modular redundancy (TMR) for voted input/output (I/O) and protection, including the field ground detector function. The control section designation is M1 (Master One), M2 (Master Two), and C (Control). M1 and M2 are independent controls, each with automatic and manual regulator functions. Either M1 or M2 may be in control of bridge firing as determined by the operator, or forced by C. In the warm backup configuration, M1 controls bridge #1, and M2 controls bridge#2. In the multibridge configuration, the master in control fires all bridges. In simplex bridge systems with redundant control, either master can fire the bridge.

--------------------------------------------------
Note added at 1 heure (2008-10-15 16:26:17 GMT)
--------------------------------------------------

Je dirais même qu'il n'est pas question de sauvegarde, mais de configuration de secours (redondante) (à chaud)