Part Number 12762 Rev 1.1 | April 30, 2014 ABOUT BACKUP CONFIGURATIONS
SRAM
24 NETWORK CONTROLLER 3E & 6E MOUNTING AND WIRING GUIDE |
longer duration outages, the battery allows the controller to perform a “controlled
shutdown”, safely backing up the station before shutting down.
Starting in the AX-3.6.nn maintenance build, the JACE can use both the NiMH
backup battery and available SRAM for backup protection (prior to this, SRAM
support required removing backup batteries). Configuring for both backup battery
and SRAM support provides the most comprehensive backup protection. This
allows the controller to “ride out” brief power outages, while also protecting against a
scenario of a battery too weak (or aged) to perform a controlled shutdown.
SRAM
The controller’s NPM3E or NPM6E processor module includes on-board SRAM and
associated circuitry, allowing “battery-less” operation. This is the same circuitry as
provided by the “SRAM option card” for earlier QNX-based JACE models, available
since the initial release of AX-3.6. Therefore, an SRAM option card is not needed (or
supported) in a T-300E or T-600E controller.
The default configuration is to use SRAM for station backup, via the platform
“DataRecoveryService” that is automatically created in the controller’s running
station. However, in some cases, a station may be a poor candidate for SRAM
support, requiring too many resources by this associated platform service. An
example is a station with many rapidly changing values all captured as histories, on
COV. In this case, you may wish to disable SRAM support, and install and use only
the optional NiMH battery pack.
For an overview, see “About Backup Configurations,” page 23. Complete NiagaraAX
details on the operation of the controller’s integral SRAM are in the JACE Data
Recovery Service (SRAM support) - Engineering Notes document.
NiMH battery pack
A custom 10-cell NiMH (nickel metal hydride) battery assembly is available as a
separately orderable option for a T-300E or T-600E controller. This battery assembly
incudes a metal bracket with the tie-wrapped NiMH battery pack. It is the same
battery assembly installed in the previous JACE 2/6 series controllers.
This battery allows the controller to continue station operation through short power
bumps, ranging from a few seconds to a minute or more in duration (up to 10
minutes, if also using SRAM). If a longer outage, the NiMH battery provides enough
run time for the unit to backup data and then shutdown. Shutdown occurs
automatically, after data is backed up to on-board flash memory.
The controller charges the battery during normal operation, until fully charged.
Typically, the charge operation completes within 18 hours. Following a power
outage, the battery is charged again, as necessary. The power and battery circuitry is
monitored by a station running on the JACE (via its PowerMonitorService). Station
alarms are generated whenever primary power is lost, or if the battery is uncharged
or unable to hold a sufficient charge.
Note A NiMH battery characteristic is to lose charge if not left in charge mode
(trickle charge). Leaving the battery unconnected, or in the unit powered
off will cause the battery to fully discharge in a matter of weeks. Note that a
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