IS200TBAOH1C - Analog Output Terminal Board

Functional Description

IS200TBAOH1C is a Discrete Input/Output Terminal Board manufactured and designed by General Electric as part of the Mark VI series used in GE speedtronic Control Systems. A total of 16 analog outputs with a 0–20 mA current range are supported by the Analog Output (TBAO) terminal board. The I/O processor, which can be local (Mark* VIe control) or remote, generates current outputs (Mark VI control). The outputs feature noise suppression circuitry to guard against surge and high-frequency noise. Six D-type cable connections and two barrier-type terminal blocks are available at TBAO for client wiring.

Mark VI Systems

The Mark VI systems' TBAO supports simplex and TMR applications and collaborates with the VAOC processor. TBAO is connected to the VME rack housing the VAOC board by cables with molded plugs. Three VOAC boards are connected to TBAO by cable in TMR systems.

Mark VIe Systems

TBAO only supports simplex applications on Mark VIe systems and is compatible with the PAOC I/O pack. The D-type connectors are used by the I/O packs, which connect to the controller over Ethernet.

Installation

A vertical mounting plate should be attached to TBAO. The two I/O terminal blocks positioned on the left of the board are where the 16 analog output wires should be directly connected. The use of a spade or ring-type lugs will allow each point to accommodate two 3.0 mm (#12AWG) wires with 300 V insulation. The 24 terminals on each block are secured by two screws. On the left-hand side of each terminal block, a shield terminal strip connected to the chassis ground is present.

Connect the following cables to TBAO:

1. Attach cables with molded plugs to the TBAO's D-type connectors and the VME rack housing the VAOC processor in Mark VI systems. Use six cables for TMR or two cables for simplex.
2. Connect the PAOC I/O packs directly to the appropriate D-type connectors on Mark VIe systems. The packs are supported by unique side mounting brackets.

Operation

The 16 analog control outputs that TBAO provides. Driven devices can be placed up to 300 m (984 ft) from the turbine control cabinet and should not have a resistance of more than 500 (900 if employing I/O packs). The D/A converter and the drivers that produce the regulated currents are found in the VAOC or PAOC. The voltage drop across a resistor on the terminal board is used to calculate the output current.

Each output's surge is suppressed and high-frequency noise is reduced by filters close to the signal exit point. The TBAO in a simplex system is depicted in the next image. As depicted in the image below, each analog current output in a TMR system is fed by the total currents from the three I/O processors. A series resistor that provides a voltage back to each I/O processor measures the overall output current. The three currents' median value, as determined by voting, is the output.