Why is the i2/ b3887 RAM memory not saved on power failure?

Issue

i2887/ b3887 Cool starts on Power failure

Product Line

Andover Continuum, SmartStruxure Solution

Environment

i2887, b3887

i2887-L-230, b3887-L-230

i2887-L-115, b3887-L-115

Cause

The i2887 and b3887 do not have a RAM battery backup.

Resolution

The i2/b3887 is one of the range of low cost i2/b3 controllers that does not have a RAM backup battery.

It has no concept of a Warm start that would save working values in the RAM. It does however have Flash Memory that allows the controller to save all of its points and programs. After a power outage these points / programs will be copied into RAM and start running from their first line (if they are Autostart) in what is called a Cool Start. Its ACCRestartMode mode will be ACCCoolStartOnly.

 

Other i2/b3 controllers that do have a RAM backup battery will allow the ACCRestartMode to be changed as required.