Alicat Scientific BC Series User manual

OPERATING MANUAL
DIGITAL MASS FLOW
CONTROLLERS
BC-Series

2
Thank you for purchasing your OEM Mass Flow Controllers.
Contact Information
Alicat Scientific
World Headquarters
7641 N Business Park Dr., Tucson, AZ 85743 USA
[email protected] · alicat.com · [phone]
India
[e-mail]
M/s Halma India Pvt. Ltd.
C/O Avire India Pvt. Ltd.
Plot #A-147, Rd. #24
Wagale Ind. Estate,
Thane (West) 400604,
Maharashtra, India
[phone]
China & SE Asia
[e-mail]
alicat.com.cn
2nd Floor, Block 63, No.
421, Hong Cao Rd,
Shanghai, PRC 200233
[phone] ext. 801
Europe
[e-mail]
Geograaf 24
6921 EW Duiven
The Netherlands
+31 (0) 26 203.1651
This device comes with a NIST traceable
calibration certificate.
This device conforms to the European Union’s
Restriction of Use of Hazardous Substances in
Electrical and Electronic Equipment (RoHS)
Directive 2011/65/EU.
This device complies with the requirements of the
Low Voltage Directive 2014/35/EU and the EMC
Directive 2014/30/EU and carries the CE Marking
accordingly.
This device complies with the requirements of the
European Union’s Waste Electrical & Electronic
Equipment (WEEE) Directive 2002/96/EC
Rev. 0 • 2020-09-25 • DOC-MANUAL-BASIS

DIGITAL MASS FLOW CONTROLLER operating manual 3
Contents
Getting Started __________________________________________4
Mounting _________________________________________4
Plumbing _______________________________________________5
Process Ports ______________________________________________5
Maximum Pressure _________________________________________ 5
Flow Controller Operation ___________________________________ 6
Power and Signal Connections ________________________6
RS-232 or RS-485 Digital Signals______________________ 7
Analog Signals _________________________________ 7
Serial Communication_____________________________________8
Establishing Communications _________________________8
Serial Terminal Application _________________________9
Unit ID and Modbus ID _______________________________9
Changing the Baud Rate __________________________ 10
Taring___________________________________________ 11
Collecting Flow Data _______________________________ 11
Commanding a New Setpoint ________________________ 12
Sending Setpoints as Floating Point Numbers_____________ 12
Sending Setpoints as Integers ______________________ 13
Creating a Setpoint Watchdog ______________________ 13
Flow Averaging ___________________________________ 14
Changing the Gas__________________________________ 14
PID Tuning _______________________________________ 15
Changing Gain Values ___________________________ 15
Tuning the PDF Control Algorithm ____________________ 16
Troubleshooting Valve Performance with PID Tuning ________ 16
Quick Command Guide _____________________________ 17
Modbus/RTU Communication _____________________________ 18
Modbus Registers _________________________________ 18
Configuration Registers __________________________ 19
Data Registers ________________________________20
Maintenance ___________________________________________ 21
Cleaning_________________________________________ 21
Recalibration _____________________________________ 21

DIGITAL MASS FLOW CONTROLLER operating manual 4
Getting Started
Mounting
No straight runs of pipe are required upstream or downstream of the flow
controller. BASIS (BC-Series) Mass Flow Controllers have mounting holes
on the bottom for convenient mounting to flat panels. The thread size of
these holes is M3. These controllers are position insensitive and can be
mounted in any orientation.

DIGITAL MASS FLOW CONTROLLER operating manual 5
Plumbing
Process Ports
Your instrument is shipped with plastic plugs fitted in the port openings. To
lessen the chance of contaminating the flow stream do not remove these
plugs until you are ready to install the device.
•If you are using a fitting that does not have a face seal, use thread-
sealing Teflon tape to prevent leakage around the port threads, but
do not wrap the first two threads. This will minimize the possibility
of getting tape into the flow stream and flow body.
•If you are using a fitting that has a face seal, there is no need to
apply Teflon tape to the threads.
!
Warning: Do not use pipe dopes or sealants on the process
connections, as these compounds can cause permanent damage to
the controller should they get into the flow stream.
When changing fittings, carefully clean any tape or debris from the port
connections.
Maximum Pressure
Using the flow controller above the maximum specified internal line
pressure will result in permanent damage to the internal sensors. If the line
pressure is above this, please use a pressure regulator upstream of the
flow controller to reduce the pressure to below the maximum internal
pressure. See the chart below for pressure limits.
Model
Max Common Mode Pressure
BC-C0100
145 PSIG
BC-C1000
145 PSIG
BC-L0020
60 PSIG

DIGITAL MASS FLOW CONTROLLER operating manual 6
Flow Controller Operation
Your flow controller can measure and control flow generated by positive
pressure and/or suction. Connect the controller so that the flow travels in
the same direction as the flow arrow, from left to right, as you look at the
front of the device.
Alicat Scientific BC-Series Mass Flow Controllers incorporate a digital
sensor with a single control valve and circuitry. The integrated control
algorithm measures the mass flow, compares it with the setpoint, and
adjusts the valve accordingly at 400 times per second.
The response time of the system will depend on the operating conditions
and the PID tuning of the device.
Power and Signal Connections
Power must be supplied through the 9-pin D-Sub connector located on top
of your BASIS device. BASIS controllers require a power supply capable of
delivering 10–30 Vdc at 200 mA.
Pin
Function
Cable
1
Not Connected Black
2
Not Connected Brown
3
Serial RS-232 RX / RS-485 B Input Signal (receive) Red
4
0–5 Vdc Analog Setpoint Input White
5
Serial RS-232 TX / RS-485 A Output Signal (send) Yellow
6
0–5 Vdc Analog Output Signal Green
7
Power In (as described above) Blue
8
Ground (common for power, digital communications, and analog signals) Orange
9
Ground (common for power, digital communications, and analog signals) Orange
Caution: Do not apply power to pins 3, 4, 5, or 6. Permanent
damage can occur.

DIGITAL MASS FLOW CONTROLLER operating manual 7
RS-232 or RS-485 Digital Signals
To use the RS-232 or RS-485 input signal, connect the RS-232 / RS-485
Output Signal (Pin 5), the RS-232 / RS-485 Input Signal (Pin 3), and Ground
(Pin 8) to your computer serial port as shown below.
9-Pin Serial Connection
9-Pin Alicat Connection
Pin
Function
Pin
Function
5
Ground
8
Ground
3
Transmit
3
Receive
2
Receive
5
Transmit
Analog Signals
These devices include a primary analog output signal, which is 0–5 Vdc
and linear over its entire range. A zero-flow condition is indicated at
approximately 0.010 Vdc and full scale flow is indicated at 5.0 Vdc. The
output voltage is linear over its entire range. Ground for this signal is
common on pin 8.

DIGITAL MASS FLOW CONTROLLER operating manual 8
Serial Communication
The device supports both ASCII-based serial commands and Modbus/RTU
IO over either a RS-232 or RS-485 serial port. The supported physical serial
protocol will be specified in the device model number. Connecting your
flow controller to a computer allows you to log the data that it generates.
This section of the manual shows you how to operate the flow controller
using ASCII commands.
Establishing Communications
After connecting your flow controller using a communications cable, you
will need to establish serial communications through a real or virtual COM
port on your computer or programmable logic computer (PLC).
•If you have connected your device to a serial port, note its COM
port number. This can be found in Windows® Device Manager.
•If you have a serial to USB adapter, plug it into your computer,
ensure the proper driver is installed, and note the COM port
number.
•The controller will be configured with the following settings:
• Baud: 38400 (default; others can be used if the computer, its
software and the controller are set for the same rate)
• Data bits: 8
• Parity: None
• Stop bits: 1
• Flow control: None
Alicat devices use ASCII commands which are easily used in a serial
terminal or integrated into a PLC.
✓
Note: In what follows,  indicates an ASCII carriage return (decimal
13, hexadecimal D). Serial commands are not case-sensitive.

DIGITAL MASS FLOW CONTROLLER operating manual 9
Serial Terminal Application
Alicat’s proprietary Serial Terminal is a preconfigured program for serial
communications that functions much like Windows’ old HyperTerminal
program. Download Serial Terminal at alicat.com/drivers for free. Once
downloaded, simply run SerialTerminal.exe. Enter the COM port number to
which your device is connected and the baud rate of the flow controller.
The default baud rate is 38400.
✓
Note: Some features of the serial terminal, such as the dump all
command, are not available for BASIS devices. All serial commands
specified in this manual will function as intended.
Unit ID and Modbus ID
The device is addressed with a single letter unit ID from A through Z, with
A being the default. All serial commands must be preceded by the unit ID,
and followed by a carriage return before they take effect. The * character
will address all devices on the serial line and can be used to query the unit
ID, if it is unknown. This should only be used if a single device is connected,
otherwise the responses will be corrupted from multiple devices trying to
write at the same time.
You can change the unit ID by typing:
Change the unit ID: [current unit ID]@=[desired unit ID]
Example: a@=b(changes unit A to unit B)
!
Warning: Care should be taken not to assign the same unit ID to
more than one device on a single COM port.
This device supports the Modbus/RTU device address from 1–247, and this
is separate from the unit ID. The factory default Modbus ID is 1.
You can read and change the Modbus ID by typing:
Read the Modbus ID: [unit ID]rm
Example: arm(reads Modbus ID on unit A)
Change the Modbus ID: [unit ID]wm=[desired Modbus ID]
Example: awm=7(changes Modbus ID to 7 on unit A)
✓
Note: When changing to a new Modbus ID, any values above the
maximum of 247 will result in the ID changing to 1.

DIGITAL MASS FLOW CONTROLLER operating manual 10
Changing the Baud Rate
BASIS units can communicate over bauds rates of 4800, 9600, 19200,
38400, 57600, or 115200. 38400 is the default baud rate.
You can read the current baud rate as well as change it by typing:
Read the baud rate: [unit ID]rb
Example: arb(reads baud rate on unit A)
Change the baud rate: [unit ID]wb=[desired baud rate,
see table]
Example: awb=2
(changes baud rate on unit A to 19200)
Value
Corresponding Baud Rate
0
4800
1
9600
2
19200
3
38400
4
57600
5
115200
✓
Note: When changing the device’s baud rate, your COM port must
change its own baud rate in time to successfully receive the
response confirming the new baud rate. If it does not, then the baud
rate will change on the device, but the response from the serial
terminal will be incomprehensible. Since the serial terminal is set to
communicate at a specific baud rate during the initial configuration,
you will have to redefine the terminal baud rate to continue
communications. This can be done using the baud
[value] command, where [value] equals the baud rate.