MKS 649B - How to Change the Pressure Output Signal Range

Chapter Four: Operation How To Change the Pressure Output Signal Range
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How To Change the Pressure Output Signal Range
The pressure output signal can be a 0 to 10 Volt (initial setting) or 0 to 5 Volt signal. To change
the range of the pressure output signal, and therefore, the set point input, you must remove the
cover of the 649 pressure controller and reposition two jumpers on the Transducer board.
Note
The range of the pressure output signal determines the range used for the
set point input signal. The initial configuration is for a 0 to 10 Volt
pressure output signal. Therefore, a set point input signal of 10 Volts is
equal to 100% of full scale. If you change the range of the pressure
output signal to 0 to 5 Volts, a 2.5 Volt set point signal would be 50% of
full scale.
1. Stop the gas flow through the 649 pressure controller.
2.
Remove the power supply and any other leads or wires attached to the connector on the
649 controller.
3.
Use a 4.8 mm hex wrench (or open-ended wrench) to remove the hex nuts on each side of
the I/O connector.
4.
Refer to Figure 6, page 21, for the location of the hex nuts on the I/O connector. Use a
Philips screwdriver to remove pairs of screws from both ends of the enclosure.
5.
Place the hex nuts and screws aside for safe keeping.
6.
Position the controller with the front side facing you, and pull up on the enclosure to
remove it.
The MKS logo is displayed on the front of the unit. The board assembly will be visible,
with the Transducer board facing you. The Control board is connected to the back of the
Transducer board.
7.
Locate the jumper block labeled “JP2” on the right-hand side of the Transducer board.
Refer to Figure 14, page 39, for the location of the “JP2” jumper block.
8.
Position the jumper vertically, according to the silk-screen on the board.
Position the jumper on the right-hand side for 0 to 10 Volt operation;
position the left-hand side for 0 to 5 Volt operation.
9.
Locate the jumper block labeled JP1, above jumper block JP2.
10.
Remove the jumper on JP1 for 10 Volt operation.
Position the jumper on the pins for 5 Volt operation.