Chapter 4
Configuration
MAN_905G_1.16
Page 62
trigger will occur for register 34. Sensitivity values are in decimal and can vary between 1
and 65535 (16-bit).
Up to 50 blocks of sensitivities can be configured. If a register is included in more than one
block, then the first sensitivity value configured will be accepted and later values ignored.
Registers which are not included in any block use the “default” sensitivity which is also user-
configurable. In the above example, the default sensitivity is 1 and is the sensitivity for all
I/O registers not included in the three blocks.
Important Note.
Sensitivity values need to be selected carefully for
analog or counting
registers as small values can result in a large number of change messages, which can
overload the radio channel. A sensitivity value of 1 in 65535 is a change of 0.0015%. If the
host device writes an analog value to a 905G every 100msec, it will change by at least 1 bit
each time. A small sensitivity value will cause a change message to be sent every 100msec.
If there are many analog values in the same situation, then there would be many change
messages every 100msec. Sensitivity values for analog I/O should be set to be greater than
the normal process noise of the signal. For example, if a flow signal has a normal process
oscillation of 2.5%, then the sensitivity should be set to 3% (or a value of 2000) to avoid
change transmissions from the process oscillations.
