Specifications

MFC-CB™ Operation and Maintenance Manual
©2001~2007 DH Instruments, a Fluke Company Page 90
Table 13. MFC-CB DEV1 and DEV2 Connector Pin Out (Continued)
MFC-CB DEV1, DEV2
25 PIN DSUB
CONNECTOR PIN NO. SIGNAL SIGNAL DESCRIPTION
11
Valve Test
Used for direct measurement of the MFC
internal valve voltage. Not available on
all MFCs.
12 Current MFC Measure
(+)
Only used for current controlled devices.
This is the mA signal that represents the
MFC’s measure.
13
Current MFC Set (+)
Only used for current controlled devices.
This is the mA signal that defines the
desired set point for the MFC. It is
frequently referred to as the “MFC control
signal” or the “MFC set point”.
14
MFC Set point (+)
Desired set point for the MFC. It is the
signal that controls the amount of gas that
the MFC will flow. Generally a 0 to 5 Volt
signal where 0 V causes the valve to close
(zero flow) and 5 V causes full scale flow.
This signal is commonly referred to as
“MFC set point”, “MFC set voltage”, “MFC
command”, or “MFC control”.
15
MFC Set point (-)
Ground reference for the MFC Set point
signal. It is frequently referred to as
“Signal Common”, or “Common”.
16
MFC Measure (-)
Ground reference for the MFC measure
signal. It is frequently referred to as
“Signal Common”, or “Common”.
17
Valve Test Common
Negative –15 Volt supply for the MFC’s
valve test circuit. Most MFCs utilize this
line by connecting it to the –15 Volt
supply line.
18
N/C No connection, no signal.
19
-15 Volts Negative MFC or MFM supply.
20
Set Point Sense (+)
Used by the MFC-CB to detect loss along
the MFC cable. Represents the positive
MFC set point as seen by the MFC. This
line should be connected to the same
point as the MFC Set point (+) line at the
MFC side of the cable.
21
N/C No connection, no signal.
22
N/C No connection, no signal.
23
N/C No connection, no signal.
24
N/C No connection, no signal.
25
N/C No connection, no signal.