User manual for RTD,TC,mV/4-20mA converter module SPT-86L
rate. While installation of the new network it is recommended to readdress all devices using
baud rate 9600 bit/s, and next change speed of all devices simultaneously, using
BROADCAST query (with address 00h).
5.4.
DETECTION OF THE PEAK VALUES
The
SPT-86L
module is equipped with peaks detection function. It can detect peaks of
the input signal and hold their values. Presets connected with this function are placed in group
of registers named ”
Hold
” (
see
LIST OF REGISTERS
). The detection of the peak can be done
if the measured signal raises and drops of value at least equal to parameter ”
HoldPeak
”.
Detected peaks are hold during the time defined by parameter ”
HoldTime
”. If a new peak will
be detected while one is hold, this new peak will be held and value holding time counter will
restarted
(fig. 5.2). If no peaks are detected while time ”
HoldTime
”
elapses
,
device returns the
current value of input signal in the peak value register (06h register).
The current output can be controlled depending on the current value of input signal (01h
register) or the peak value (06h register,
see
LIST OF REGISTERS
).
Fig. 5.2. Process of peaks detection
6.
MEASURED VALUES CALCULATION
All calculations in the following examples are made for the input in 0-100 mV mode.
For temperature inputs (TC and RTD) only linear characteristic is available.
The first step to compute the result of measure is the calculation of the normalized result
(it means result of 0-1 range). To do it, the begin of the input range (0 mV for 0-100 mV range)
must be subtracted from measured value. Next, received result must be divided by the width of
the input range (it means 100 mV for 0-100 mV range). So normalized result can be expressed
by expressions:
U
n
=
U
inp.
100
for range
0
÷
100
mV
11
”HoldTime”
measure
time
”HoldTime”
”HoldPeak”
”HoldPeak”
real measurement result
value in register 06h
i
