Operating Instructions
Table Of Contents
- 1 Scope of supply
- 2 Order numbers
- 3 Basic safety instructions
- 4 Introduction
- 5 Installing the OTT SVR 100
- 6 SDI-12-commands and responses
- 7 Performing maintenance work
- 8 Repairs
- 9 Information on disposal of old devices
- 10 Troubleshooting
- 11 Technical Data
- Appendix A – Connecting the OTT SVR 100 to OTT netDLvia the RS-485 interface
- Appendix B – Wall bracket dimensions/mounting hole positions
- Appendix C – Note on the declaration of conformity
- Appendix D – RS-485 interface with Modbus protocol (RTU)
- Appendix E – OTT SVR 100 Operating Program
6.2 Advanced SDI-12 commands
Command Response Description
!
Set/read internal filter type
aOAA<value>!
aOAA!
a<value><CR><LF>
a<value><CR><LF>Calculation
S
et internal filter type
Read internal filter type
a – Sensor address
<value> – 0 = IIR filter (Infinite Impulse Response filter)
1 = Floating mean
Factory setting: 1
The OTT SVR 100 determines approx. 20 individual mea-
sured values for the flow velocity per second. Depending on
factors such as the roughness of the water surface, wind
influence, precipitation or turbulence, the individual mea-
sured values can be very scattered. The internal filter allows
them to be "smoothed". In principle, both filter types lead to
very similar results, but the IIR filter responds faster if there
are significant changes in flow velocity. When using the
floating mean, you can specify the number of individual
measured values (aOAC<value>!command). This filter
works totally independently of the "average flow velocity"
(value 1 in the response to the aD0!command)
IIR filter calculation:
v
filtered
(t) = v
current
(t)
*
Q + v
filtered
(t – 1)
*
(1 – Q) Q = 1/3
!
Set/read measuring sensitivity
aOAB<value>!
aOAB!
a<value><CR><LF>
a<value><CR><LF>
Set measuring sensitivity
Read measuring sensitivity
a – Sensor address
<value> – bb
Input/output without leading zeroes
Value range: 10 … 40
Factory setting: 14
You can use this command to set the sensitivity of the radar
sensor. The advantage of a high sensitivity (low value) is that
measurements can be taken on very smooth water surfaces.
On the other hand, there is a risk that unwanted effects will
also be recorded, for example movement of vegetation on
the bank.
For normal applications, you should not change the factory
setting.
!
Set/read internal filter length (filter type: floating mean)
aOAC<value>!
aOAC!
a<value><CR><LF>
a<value><CR><LF>
Set filter length
Read filter length
a – Sensor address
<value> – bbb
Input/output without leading zeroes
Value range: 1; 16 … 256
Factory setting: 50
You can use this command to specify the number of individ-
ual measured values from which the internal filter calculates
a floating mean (prerequisite: aOAA1!).
The setting "1" deactivates the internal filter.
20