GE IS200VAOCH1C Analog Output Board

GE IS200VAOCH1C Analog Output Board

Part Number IS200VAOCH1C Manufacturer General Electric Country of Manufacture As Per GE Manufacturing Policy Series Mark VIe Function Module Availability In StockThe IS200VAOCH1C is a VME Analog Output Card developed by GE for their Mark VI system. The MKVI is one of GE's later Speedtronic steam/gas heavy-duty turbine management systems, released over several decades. The board is installed in a VME rack and receives digital values from the controller via the VME backplane. These values are converted to analog output currents and sent to the terminal board of the VAOC, where they are measured and fed back to the VAOC for control. 

It should be noted that the component is a second-generation VAOC board with higher load resistance on the first eight output circuits. This enables operation with a load resistance of 800, as opposed to 500 of the remaining eight output circuits. On the board surface of the PCB, there are several connectors, including two backplanes. The board contains sixteen relays, which are located near the front right corner. A relay diagram is included with each of these components. 

On the board's surface are various types of integrated circuits, such as oscillating chips, FPGAs (field programmable gate arrays), and SRAM chips. It contains resistors, diodes, and capacitors of varying resistance/capacitance made from various materials. The board has a faceplate that is connected to the board via three screw connections. The faceplate contains three LED components labeled Run, Fail, and Status. These LEDs are green, red, and orange, in that order. The alarm states, board configuration, and installation guidelines can be found in GE publication GEH-6421. Manuals and datasheets referencing this board number may also be useful for installation or maintenance guidance.

SPECIFICATIONS:

Part Number: IS200VAOCH1C
Manufacturer: General Electric
Series: Mark VI
Product Type: Analog Output Board
Number of channels: 16
Analog outputs: 0-20 mA
Number of CPFX Boards Per Phase Leg: 1
Number of Plug Connectors: 2, J1 and J2
Mounting: DIN-rail mounting
Technology: Surface mount
Operating temperature: -30° to 65°C
Size: 15.9 cm high x 10.2 cm
Repair: 3-7 Day
Availability: In Stock
Country of Origin: United States
Manual: GEH-6421M

FUNCTIONAL DESCRIPTION:

IS200VAOCH1C is an Analog Output Board manufactured and designed by General Electric as part of the Mark VI Series used in GE Speedtronic Control Systems. The Analog Output (VAOC) board controls 16 analog, 20 mA outputs. Outputs are wired to analog output terminal board(s) (TBAO or DTAO). Cables with molded plugs connect the terminal board to the VME rack where the VAOC processor board is located. VAOC receives digital values from the controller over the VME backplane from the VCMI, converts these to analog output currents, and sends them to the terminal board. The actual output current is measured on the terminal board and fed back to VAOC where it is controlled. In triple modular redundant (TMR) applications, control signals are fanned to the same terminal board from three VME board racks R, S, and T, as shown in the following figure. Six cables are required to support all 16 outputs. Each final current output is the median selection of the three currents in the three VAOCs. This median select circuit is in each VAOC.

COMPATIBILITY:

There are two generations of the VAOC board with corresponding terminal boards. The original VAOC includes all versions before and including VAOCH1B. When driving 20 mA outputs, these boards support up to a 500 Ω load resistance at the end of 1000 ft (304.8 m) of #18 wire. This generation requires terminal board TBAOH1B or earlier for proper operation, or any revision of DTAI. The newest VAOC board, VAOCH1C, and any subsequent releases support higher load resistance on the first eight output circuits. For 20 mA outputs, a drive voltage of up to 18 V is available at the terminal board screw terminals. This permits operation with an 800 Ω load resistance with 1000 ft (304.8 m) of #18 wire with margin. The second set of eight output circuits retains the 500 Ω rating of the original VAOC. VAOCH1C requires TBAOH1C or later.

OPERATION:

VAOC supports 16 analog 0-20 mA outputs. The VAOC contains the D/A converter and driver that generates the controlled currents, as shown in the following figure. The output current is measured by the voltage drop across a resistor on the terminal board. Terminal board outputs have noise suppression circuitry to protect against surge and high-frequency noise. The following figure shows VAOC circuitry in a simplex arrangement. In a TMR system, each analog current output is fed by the sum of the currents from the three VAOCs. The total output current is measured with a series resistor that feeds a voltage back to each VAOC. The resulting output is the voted middle value (median) of the three currents. If one output fails, the other two pick up the current to the correct value. In the event of a circuit malfunction that cannot be cleared by a command from the processor, the circuit is disconnected by opening the shutdown relay contacts. This isolation function is only operational when configured for TMR operation.