- Emerson Remote Terminal Unit Instruction Manual

2-26 / Installation & Operation CI-ControlWave Express
2.3.8 Operation of the Lithium Backup Coin-cell Battery
CPU/System Controller Boards are equipped with a Coin-cell Socket (S1) that
accommodates a 3.0V, 300 mA-hr lithium coin cell. A supervisory circuit on the
CPU/System Controller Board is used to switch to battery power when the regulated 3.3Vdc
VCC falls out of specification. The CPU/System Controller Board switches the battery
voltage to the VBAT3.3 hardware signal, which provides backup power for the real-time
clock (RTC) and the system SRAM on the CPU Module.
The system SRAM has a standby current draw of 20uA maximum for each part. For a unit
containing 2MB of SRAM, a worst-case current draw of 42uA allows a battery life of
approximately 9000 hours.
Jumper W3 on the CPU/System Controller Board must be installed on terminals 1 and 2 to
enable the battery. For maximum shelf life, the battery may be isolated from the circuit by
install Jumper W3 on terminals 2 and 3.
CPU/System Controller Boards are shipped with the Lithium backup battery installed. To
remove the backup battery, pry up the Battery Securing Tab on the Coin-cell Battery
Socket and then remove the battery using a pair of tweezers or needle-nose pliers. Install
the replacement battery. Note: This step will not be required until units have been in
operation for an extended period of time (normally many years) as the battery life is
approximately 9000 hours of backup service. (Power is drawn from the battery when the
unit looses power).
NOTE:
If the Lithium backup battery is disconnected or removed when power is off the
contents of SRAM (on the CPU/System Controller Board) will not be retained.
Once a Lithium backup battery has been removed, do not install a replacement
battery for at least one minute unless SW2-5 on the CPU/System Controller Board
has been set OFF.
2.4 OPERATIONAL DETAILS
ControlWave Express RTUs are shipped from the factory with firmware that allows the
unit to be configured in conjunction with an IEC 61131, application program. This section
provides information as follows:
- Steps required to download the application and place the unit into ‘Run’ mode.
- Steps required to download system firmware.
- Operation of the CPU/System Controller Board’s Mode Switch (SW1)
- Soft Switch Configurations and Communication Ports
Operational details on ControlWave Express LEDs (and optional LCD Displays) and use of
the Bristol WINDIAG program for fault isolation are provided in Chapter 3.
2.4.1 Downloading the Application
Any ControlWave Express must have a configured ControlWave project (application) before it
can be placed into operation. For units not shipped with a standard application, this will
require connection of the ControlWave Express to a PC running ControlWave Designer and
OpenBSI software. Configuration of the application must be performed by an individual
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