Instruction manual

Instruction Manual Smart-Trak
®
50 Series
IM-50 Rev. A.2 26
Chapter 4: Analog Operation
Your Smart-Trak
®
50 Series instrument has an optional analog mode
This chapter will discuss Analog Operation. The analog output option is a 4-20 mA or 0- 5
VDC output signal corresponding to 0% to 100% of the mass flow full scale range.
For mass flow controllers, one analog setpoint signal and one analog output signal of either 4-
20 mA or 0-5 VDC may be chosen to set the mass flow rate to any desired value within the
range of the device, or to read mass flow value as an outputted analog value. This input signal
must be a direct linear representation of 0% to 100% of the desired gas mass flow full scale
value. Your unit was programmed for either 4-20 mA or 0-5 VDC, not both; please refer to
the data label or calibration certificate for this information
2-2.
Analog Operation, Mass Flow Meter
After your instrument is installed and the system has undergone a complete leak check as
discussed in detail in Chapter 2, you are ready to supply power.
Power Your Instrument: Provide adequate power per Figure 2-2. Apply power using
Sierra’s power supply or your own power source. Hook up the analog output per Figure 2-2
if desired, or use the RS communications or display (optional) to read mass flow value. Let
the instrument warm up for at least 15 minutes for optimal performance.
Analog Operation, Mass Flow Controller
After your instrument is installed and the system has undergone a complete leak check as
discussed in detail in Chapter 2, follow these steps:
1. The valve will remain closed until power is supplied. See Chapter 2 for wiring
instructions. Remember that the valve in the Smart-Trak
®
50 Series is not a positive
shut-off device. When power is applied, the flow control valve will operate per any
instructions it receives. When the Smart-Trak
®
50 Series is delivered, the valve will
be closed. However, upon subsequent power-ups, the valve will return to the state it
was in the last time the instrument was operated.
CAUTION! If you do not know the value of the setpoint or the valve state given to the Smart-
Trak
®
50 Series when it was last operated, you must assume that the valve will open when
power is applied. TAKE NECESSARY PRECAUTIONS. You may use the Smart-Trak
®
50
Series Software to check the setpoint or the valve state currently on your instrument. See
Chapter 4 or Chapter 5 for information on Setpoint and Valve State.
2. Power Your Instrument: Provide adequate power per Figure 2-2. Apply power
using Sierra’s power supply or your own power source. Let the instrument warm
up for at least 15 minutes for optimal performance.