IS200VAOCH1B

IS200VAOCH1B is an Analog Output Board developed by GE. The Analog Output Board is in handle of 16 analog 20 mA outputs. These outputs are connected to the Analog Output Terminal Board via two terminal blocks (TBAO). Cables with molded plugs link the terminal board to the VME rack, which contains the processor board. It receives digital data from the controller through the VME backplane and converts them to analog output currents before sending them to the TBAO.

Features

• On the terminal board, the actual output current is measured and passed back to VAOC, where it is managed.
• Control signals are fanned into the same terminal board from three VME board racks R, S, and T in TMR applications.
• TMR requires six cables to support all 16 outputs. Each final current output is the median select of the three currents in the three VAOCs, and each has this median select circuit.
• Cable connections to the TBAO terminal boards are established at the lower J3 and J4 connectors on the VME rack. To secure the cables, they are latching connections.

Installation

1. Turn off the VME I/O processor rack.
2. Insert the VAOC board and use your hands to press the top and bottom levers in to seat the edge connectors.
3. Tighten the captive screws on the front panel's top and bottom.
4. Start the VME rack and look at the diagnostic lights on the front panel.

Operation

• The VAOC has 16 analog 0-20 mA outputs. The D/A converter and driver that generates the regulated currents are housed in the VAOC.
• The voltage drop across a resistor on the terminal board is used to calculate the output current.

Compatibility

• The VAOC board and accompanying terminal boards come in two generations. All VAOC iterations up to and including VAOCH1B are considered to be the original VAOC. These boards can sustain up to 500 W of load resistance at the end of 1000 feet of #18 wire while driving 20 mA outputs. For optimal operation, this generation of board needs a terminal board TBAOH1B or earlier. Additionally, they are compatible with all DTAI terminal board revisions.
• Each analog current output in a TMR system is fed by the combined currents from the three VAOCs. With the help of a series resistor that feeds a voltage back to each VAOC, the total output current is measured. The three currents' median value, as determined by voting, is the output. The other two pick up the current to the right value if one output fails.
• In the event of a circuit malfunction that cannot be resolved by a CPU order, the circuit is shut down by opening the contacts on the shutdown relay. Only when setup for TMR operation is this isolation feature usable.