Akytec TRM210, User Manual

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Operation and Configuration
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If in-L < in-H , then
𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑣𝑣𝑀𝑀𝑣𝑣𝑀𝑀𝑀𝑀 = 𝒊𝒊𝒊𝒊 – 𝑳𝑳 +
(
𝒊𝒊𝒊𝒊 – 𝑯𝑯 − 𝒊𝒊𝒊𝒊 – 𝑳𝑳
)
∗ ( 𝑆𝑆
𝑖𝑖
− 𝑆𝑆
𝑚𝑚𝑖𝑖𝑚𝑚
)
𝑆𝑆
𝑚𝑚𝑚𝑚𝑚𝑚
− 𝑆𝑆
𝑚𝑚𝑖𝑖𝑚𝑚
If in-L > in-H , then
𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 𝑣𝑣𝑀𝑀𝑣𝑣𝑀𝑀𝑀𝑀 = 𝒊𝒊𝒊𝒊 – 𝑳𝑳 −
( 𝒊𝒊𝒊𝒊 – 𝑳𝑳 − 𝒊𝒊𝒊𝒊 – 𝑯𝑯 ) ∗ ( 𝑆𝑆
𝑖𝑖
− 𝑆𝑆
𝑚𝑚𝑖𝑖𝑚𝑚
)
𝑆𝑆
𝑚𝑚𝑚𝑚𝑚𝑚
− 𝑆𝑆
𝑚𝑚𝑖𝑖𝑚𝑚
where
S
max
– max. input signal (for example, 20 for 4-20 mA signal)
S
min
– min. input signal (for example, 4 for 4-20 mA signal)
S
i
– current signal value
Note:
After the Signal limits are set so that in-L > in-H , the Setpoint limits SL-L , SL-H and the
Retransmission limits An-L , An-H ( init group) have to be set again (see 6.9, 6.12)
6.6 Filter
The digital filter consists of two stages.
1. The Comparator is used at the first stage to detect apparent "gaps" or "outliers"
in the input signal. The Filter bandwidth for the comparator should be specified in the
parameter
Fb in measuring units within the range 0…9999. The filter is disabled if the
bandwidth is set to 0.
The difference between the last two measurements T
i
and T
i-1
is determined and com-
pared with the bandwidth. If the difference exceeds the bandwidth, the last measurement
T
i
will be replaced with the (T
i-1
+ Fb ) and the bandwidth will be doubled to smooth the
characteristic curve. A smaller filter bandwidth slows down the response to input signal
variations (Fig. 6.4).
It is recommended to increase the filter bandwidth or disable the parameter when a low
level of interference or rapidly varying process.
If the process signal has high interferences, decrease the bandwidth to reduce the impact
on the process.
Fig. 6.4 Filter bandwidth
2. The Damping with the parameter inF is used at the second stage. The filter time
constant can be set within the range 1…999 seconds. The higher the value, the higher
the noise resistance and the slower the output response are. When the value is set to 0,
the damping is deactivated.
without filter
with filter
t, s
T, °C
Fb
T
i-1
T
i
t
i-1
t
i
t
i