Brooks Instrument SLAMf Series - Manual (Page 29)

2-5
Section 2 - Installation Installation and Operation Manual
X-TMF-SLAMf-MFC-eng
Part Number: 541B032AAG
April, 2013
Brooks ® Digital MFC's and MFM's
All thermal mass flow controllers are factory tested with stable and equal
ambient and process temperatures. If the process temperature does not
equal the ambient temperature, the bypass ratio/accuracy will be affected.
When a hot or cold process fluid is being measured, ensure that the piping
system is designed to allow the gas temperature to equalize with the flow
controller ambient temperature.
For more information, please contact the Brooks Technical Service group.
2-10 Electrical Interface
The setpoint signal is supplied as a 0(1) to 5 Vdc or 0(4)-20 mA analog
signal. All signals are supplied via the 15-pin Terminal Strip. For an analog
unit the minimum set of connections which must be made to the MFC and
MFM includes +13.5 - 27 Vdc, supply common, and a setpoint signal.
The Brooks Digital electrical interface is designed to facilitate
low-loss, quiet signal connections. Separate returns (commons) are
supplied for the analog setpoint, analog flow signal, and the power supply.
These commons are electrically connected together on the PC board.
Analog I/O Versions
• Signal Common
• Signal Output (Voltage or Current)
• +13.5 - 27 Vdc Supply
• Setpoint Input (Voltage or Current)
• Setpoint Common
• Supply Common
• Chassis Ground (via unit body)
Refer to Figure 2-1 for pin connections
Refer to Figures 2-2, 2-3 and 2-4 for electrical I/O connections
(The Brook’s MFC acts as a current sink to a setpoint input signal. The 0/4-
20 mA setpoint signal should be “driven” into the MFC input by a controlled
current source. Reference Brook’s device specifications for the setpoint
input impedance.)
(The Brook’s MFC acts as the current source when providing a 0/4-20 mA
output signal to the load. The output signal is “driven” by the MFC into the
customer load. Reference Brook’s device specifications for maximum load
capacity.)