Oldham iTrans, User Manual, Page: 60 / 88

ModBus Interface iTrans Fixed Point Single/Dual Gas Monitor
6-6 iTrans User Manual (P/N: 77023554-1)
Addr
Inst
R/W
Host
R/W
Range Description
minutes from $00 to $3C (00 to 60). Note that
the seconds default to zero ($00) each time the
hours and minutes are set.
Examples:
13:05 = $0D05
24:00 = $1800
40124 R R/W $0000 to $FFFF Low Alarm Display Setting
Holds the value of the gas reading at which the
low alarm display will activate.
40125 R R/W $0000 to $FFFF
High Alarm Display Setting
Holds the value of the gas reading at which the
high alarm display will activate.
40126 R R/W $0000 to $03E8 Cal Gas Value
Holds the value of the calibration gas to be used
on the instrument. The range is from $0000 to
$03E8 (0 to 1000
10
).
40127 R/W R $0000 to $FFFF Loop High Scaling
Holds a value which indicates the gas reading
represented by a 20 mA loop output signal. The
range is from $0000 to $FFFF.
440102
R R $0000 to $FFFF
WX Scaled Reading
Use with WX series controller.
NOTE: To get the ModBus reading, register 40103 must be read as well as
register 40102. Register 40103 specifies where the decimal should be placed.
6.4. ModBus Resources
ModBus is a public protocol that can be freely adopted by any developer or
manufacturer desiring to implement it. While a detailed discussion of ModBus
protocol is beyond the scope of this manual, there are a number of up-to-date
resources available on the internet for those wishing to investigate ModBus further.
The most complete resource is www.modbus.org.