Prolla security droid

Prolla Security droids were the production of Prolla factories, that were used mainly as mining droids around 33 BBY, but later were converted into battle droids during the occupation of Anarmar in 31 BBY, and assassin and security droids in 23 BBY.

History
In 31 BBY the mining world of Prolla, that was part of the Senb'An'Tiin Confederacy, declared its independence, but the Confederate institutions denied the right of Prolla to secede from the Union just like that. In order to force others acknowledge Prolla's sovereignty, the local authoritites modified the mining droids into battle units, that occupied the city in short terms.

In reality the Prolla droids belonged to the Trade Federation concept of new battle droids, that were replaced by a more successful model of B1 battle droids. The plans were sent by Darth Sidious to Prolla, where ZID-17, a droid assistant of the dark jedi Trillak, convinced the Prollians to start the invasion.

ZID-17 also prepared a special protocol, that allowed him to control all the battle droids on Anarmar, as well as all military turrets. The droid didn't manage to finish the installation however, and the droids were destroyed in a battle afterwards.

During the Clone Wars the Prollians created a cheaper version of Prolla Security droids (Phase 3 droids), that served mainly as body guards for the Elecrian revolutionaries. Trade Federation sponsored the project, but its own battle droids were sent to Elecria in order to stop the arriving Senb'An'Tiin forces.

The majority of these security droids were completely destroyed by the Republic forces during the Battle for Elecria.