Brooks Instrument 5850EM - Manual (Page 37)

3-13
Brooks ® Models 5964, 5850EM
Section 3 Operation Installation and Operation Manual
X-TMF-5964-5850EM-MFC-eng
Part Number: 541B121AHG
November, 2008
Five-Volt Reference Output/Valve Drive Configuration
The 5 Volt reference output is required if a potentiometer is to be used to
generate the Command Signal. On Card Edge PC Boards, Pin 10 can be
jumper selected as any of three mutually exclusive functions, 5 Volt
reference output, external valve return or “not used.” In the "not used"
state Pin 10 is connected to Circuit Common.
Do not ground the 5 Volt reference output when it is enabled.
Improper operation of the printed circuit board will result.
CAUTION
The external valve return is used to minimize the effect of resistance in the
connection wiring. If the “external valve return” feature is not enabled, the
valve voltage is returned internally on the printed circuit board and the
connection wiring resistance must be less than 0.2 ohms.
a. Card Edge Connector Version
On the enhanced response PC Board, Pin 10 is configured using the J1
black and yellow jumpers. On the standard response PC Boards Pin 10
is configured using the J3 black and J8 yellow jumpers. Refer to Figure
3-5 or 3-6 as applicable for jumper configurations.
b. D-Connector - Voltage I/O Version Only
The valve drive is configured using the J3 black jumper. The 5 Volt
reference is always available on Pin 11. Refer to Figures 3-7 and 3-8 as
applicable for jumper configurations.
c. D-Connector - Current I/O Version
The current I/O PC Board provides a 5 Volt reference on Pin 11 at all
times. The external valve return is not available with this version. Valve
voltage is always returned internally on the printed circuit board. Refer
to Figures 2-4 and 3-9.
Valve Override
Allows full opening and closing of the control valve, independent of the
command input. The valve override for normally closed and normally open
mass flow controllers is as follows:
a. To open the valve, apply +15 Vdc supply voltage to the valve override pin.
b. To close the valve, apply -15 Vdc supply voltage to the valve override pin.
c. Isolating the valve override pin returns the controller to normal opera-
tion. The valve override function is activated by applying the appropri-
ate voltage to Pin 9 for Card Edge versions or Pin 12 for D-
Connector versions.