Accutron FlowTrax IS User Manual

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Section 4: Modbus
The RS485 interface in the Accutron IS is optically isolated from the rest of the unit. This is why an
external source of 5VDC is required.
Note: Do not poll faster than every 500ms.
The default Modbus RS485 settings are:
Modbus Address: 1 (3A)
Baud Rate: 19200 (3B)
Parity: None (3C)
Stop Bits: 1 (3D)
These settings can be changed using the navigation buttons located on the main circuit board. Refer to
the flow chart on page 14. Under the diagnostics menu, sections 3A, 3B and 3C all deal with adjusting
the Modbus settings.5.1 Boot Up and Discovery Mode
4.1 Modbus Register
To change unit ID, go into your menu under Diag, option 3A. To change your baud rate, go to Diag,
option 3B. To change parity, go to Diag, option 3C.
Register Addr.
#
Description
Type
R/W
Comment
40001
0,1
Airflow reading
float
Read only
40003
2
Airflow reading
int
Read only
0.1 unit precision
40004
3
Flow units
unit
Read only
See below for more details
40005
4,5
4-20mA output
float
Read only
40007
6
4-20mA output
int
Read only
0.001 unit precision
40008
7
Error code
unit
Read only
See below for more details
Flow Units (Register 40004)
• 0 = m/s
• 1 = kcfm
• 2 = cfm
• 3 = m*3/s
• 4 = fpm
• 5 = usec
Airflow Reading (40003), and 4-20mA output (40007)
The range for these registers is from -32768 to 32767. Anything greater than these values will default to
the maximum.
Error code (Register 40008)
• 0 = good reading
• 10 = obstruction. Check sensors
• 20 = above full scale

Accutron FlowTrax IS Specifications

General

Brand	Accutron
Model	FlowTrax IS
Category	Measuring Instruments
Language	English