- Emerson Remote Terminal Unit Instruction Manual

3-2 / Service CI-ControlWave Express
3.2.2 Removal/Replacement of the CPU/System Controller Board & the
Process I/O Board
1. Loosen the two Thumb Screws and remove the Removable Card Edge Cover.
2. If the ControlWave Express is running, place any critical control processes under
manual control and shut down the unit by disconnecting power to the CPU/System
Controller Board Assembly at TB1 and, if applicable, TB2.
3. Disconnect all removable card edge connectors from the CPU/System Controller
Board and the Process I/O Board making sure they are identified so they can be
returned to their assigned connectors.
4. If present, disconnect the Keypad or Keypad/Display cable from connector J2 on the
CPU/System Controller Board.
5. Carefully slide the boards out of the Enclosure/Mounting Chassis.
6. If either the CPU/System Controller Board or Process I/O Board is to be replaced,
the two units must be separated from each. Use a pair of needle nose pliers to
squeeze the pair of tabs (associated with each of the six nylon mounting posts) while
gently pulling the CPU/System Controller Board away from the Process I/O Board.
Carefully unplug the boards from their interface connectors. The replacement boards
must be aligned with each other and pressed together such that the interface
connectors and mounting posts properly mate and then must be squeezed together
such that the mounting post tabs capture the CPU/System Controller Board.
7. To install these boards, power must be off. Align the boards (assembly) with the
Enclosure/Mounting Chassis guides (such that the Process I/O Board is adjacent to
the bottom of the unit and then slide the boards (assembly) into the unit.
8. Replace all cables removed in steps 2 through 4.
9. Replace the Removable Card Edge Cover and tighten the two Thumb Screws. Apply
power and test the unit.
3.3 TROUBLESHOOTING TIPS
3.3.1 CPU/System Controller Board Voltage Checks
One bulk power source or an internal battery (Primary Power System) can be connected to
the CPU/System Controller Board Assembly. Connector TB1 provides 2 input terminal
connections for bulk power (see Figure 3-3):
TB1-3 = (+VIN) (+5.4V to +16V for 6Vdc supply) (+11.4V to +16V for 12Vdc supply) (+21.8V
to +28V for 24Vdc supply)
TB1-4 = Chassis Ground - CHASSIS
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