Bronkhorst LIQUI-FLOW mini Quick Start - Manual

Doc nr.: 9.17.066C Date: 05-07-2013
Quick Installation Guide
7c. Bus / Digital RS485 operation
With digital operation over RS485 a bus-system with multiple instruments can be set up. Refer to the “Instruction
Manual LIQUI-FLOW
TM
mini series” for possible systems.
8. Micro-switch operation
Using the micro-switch on the instruments, several actions can be monitored
and started. The green LED is used for status indication. The red LED is used
for errors/warnings/messages. The micro-switch can be used to start several
actions, such as auto-zero, restore factory settings and bus-initialisation
actions, if applicable. See specific zero-procedure below and section 3.3 of
the Instruction Manual for more details.
Multi-functional switch
Status LED
Error/Warning LED
Unless specified otherwise, the LIQUI-FLOW
TM
mini instrument is set for RS232 communication at 38k4 baud on
node address 03 by default.
Warm-up time:
Let the LIQUI-FLOW
TM
mini warm-up for at least 30 minutes for best accuracy.
Do not apply pressure until electrical connections are made. When applying pressure to the system, avoid pressure
shocks in the system and increase pressure gradually. Also decrease pressure gradually when required.
9. Purging
In systems for use with toxic or other dangerous fluids, purging for at least 30 minutes with a dry, inert gas (like
Nitrogen or Argon) is absolutely necessary before use. After use with toxic or other dangerous fluids, complete
purging is also required before exposing the system to air.
10. Zeroing (optional)
The zero point of each instrument is factory adjusted. If required the zero point can be re-adjusted over RS232 or
by means of using the micro-switch. Procedure for zeroing by-micro switch:
Warm-up, pressure up the system and fill the instrument according to the process conditions.
Make sure no flow is going through the instrument by closing valves near the instrument.
The setpoint must be zero.
Press micro-switch and hold it. After a short time the red LED will go ON and OFF, then the green LED will go ON.
At that moment release the micro-switch.
The zeroing procedure will start at that moment and the green LED will blink fast. The zeroing procedure waits
for a stable signal and saves the zero. If the signal is not stable, zeroing will take long and the nearest point to
zero is accepted. The procedure will take approximately 10 seconds.
When the indication is showing 0% signal and the green indication LED is burning continuously again, the
zeroing action was successful.
Ready
Your LIQUI-FLOW
TM
mini instrument is now ready for operation.