SetSpecialMode
Command number: 136
Number of parameters: 2
Bytes sent by the GSV: 0
With the Special-Mode-Register some special features of the GSV-21 can be set.
The content of high byte is shown in the following table:
MSB
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
NoiseCut
AutoZero x
x
x
AbsMax
LngEn
Storing Behaviour
Storing Behaviour:
If =1, all changes of all operating parameters are stored in the non volatile EEPROM
memory immediately after changing them. If =0, most operating parameters are stored after the device is
switched off. If power-on-cycles (switching on and off) are done more often than changing of values will be
done, setting of this flag is recommended. If changing of values is done more often, leave it =0 (default
setting).
LngEn
: =1: Display menu language is english. =0: Display menu language is german
AbsMax
: If Max-mode also set (s. SetMode): =1: The maximum of the absolute value of the measuring value
is transmitted
AutoZero
: (only if available, see
GetCommandAvailable
, otherwise X): =1: Automatic periodical zero-point
adjustment enabled, see
SetAutoZeroCounter
, command 150.
NoiseCut:
(only if available, see GetCommandAvailable, otherwise X): =1: Noise Supression enabled, see
SetNoiceCutThreshold, command 148.
The content of the low byte is shown in the table below:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
LSB
Unipolar-
Mode
x
FIR_N5
AutoFilt
Select.TX FIR-Filter
MW-Filter
Slow
Slow:
=1: Slow mode enabled. In this mode, mesuring values are transmitted with data periods >= 1 s. This
period is communicated with the commands 134 / 135. The data rate communicated with commands
138/139, 3/7 and 18/22 is not valid in this mode.
MW- Filter
: Read-Only Flag: Is =1, if Mwsum is >1 (see commands 138, 139)
FIR- Filter
: =1: Turns on FIR-Filter; a digital low pass filter, which takes place after the firmware-internal
decimating average filter. Its cut-off frequency depends on the measuring data rate.
Select.TX:
Selective Transmission: If this flag is =1 and the maximum value mode is enabled (see command
Set Mode
), only new maximum values will be transmitted, in order to avoid redundancy transmission.
AutoFilt: if
=1 (default setting), the analogue pre filter will be set automatically according to the datarate
Fdata.
In this case the cut-off frequency fg of the analogue filter will be set as follows:
switches fg = 3,5 Hz
switches fg = 260 Hz
switches fg = 1,7 kHz
FIR-Filter off
if Fdata <= 7,14/s
if 7,14/s < Fdata < 625/s
if Fdata >= 625/s
FIR-Filter on
if Fdata <= 15/s
if 15/s < Fdata < 1071/s
if Fdata >= 1071/s
FIR_N5:
Defines the characteristic of the digital FIR-filter, if the FIR-Filter is on (Bit 2=1). If the FIR_N5 is =0,
it is a second order FIR filter, its -3dB-cut-off frequency is = Datarate * 0,18 and its transfer function is gentle,
without overshot in the step response its operating time is only 3 measuring values. If FIR_N5 =1, it's a 5th
order FIR filter. Its cut-off frequency is = datarate * 0,25 and its transfer function is much steeper in the
attenuating band, but with 6% overshoot in the step response; and the operating time takes 6 measuring
values. That's why the FIR-Filter 5. order is more recommendable at higher data rates, if (for example for
vibration analysis) a quite linear frequency response in the transmission range and a steep tapered is desired
in the attenuating band.
Unipolar- Mode
: Read-Only Flag. Shows if the unipolar- or bipolar-Mode
is set, see commands 20/21.
x
: Reserved, do not change; should be the same as the value read, see GetSpecialMode.
ME-Meßsysteme GmbH, Neuendorfstr. 18a, D-16761 Hennigsdorf
40
Phone 03302 78620 60, Fax 03302 78620 69,
,
www.me-systeme.de/en
Summary of Contents for GSV-2AS
Page 65: ......
