13
DP20 Economical Multisignal meter
Instruction Manual
•
Measuring process signals
The instrument accepts the measure of process signals
in 4/20 mA and 0/10 Vdc. The instrument provides
excitation voltage to power up transducers.
•
Scaling
The instrument allows to scale the reading to 4 digits (9999 / -1999)
with configurable decimal point to any position. The ‘second scaling’
function can also be used (see section 1.24).
•
Maximum oversignal
‘Maximum oversignal’ is the maximum signal accepted by the in-
strument. Higher signal values may cause instrument damage. Low-
er values are non destructive but may be out of accuracy specifica-
tions.
•
Response times
The response time to a signal step is 300 mSeconds, independent of
the signal range selected.
•
Terminal 5 ‘multifunction’ - ‘Vexc’ or ‘External control’
To configure the +15 Vdc excitation voltage at terminal 5, set internal
jumper ‘T’ at position 1-2 (see section 1.9). Transducers with a
consumption of up to 30 mA can be powered from this terminal.
To configure the ‘EK’ external contact function at terminal 5, set
internal jumper ‘T’ at position 4-5 (see section 1.9). See section 1.9
for a list of available functions.
1.16 Process measures
1.17 Measuring frequency
•
Start-up, connections and jumpers
For instrument start-up follow the steps listed at section 1.7. Signal
connections are indicated at section 1.5. Location for internal
jumpers is indicated at section 1.9.
See below a list of typical connections :
mA +
mA -
1 2 3 4 5
•
signal 4/20 mA active
signal (mA-)
•
signal 4/20 mA passive
+15 Vdc (mA+)
1 2 3 4 5
+Vdc
common
•
signal 0/10 Vdc passive
+15 Vdc
1 2 3 4 5
+Vdc
common
•
signal 0/10 Vdc active
1 2 3 4 5
•
How the instrument measures frequency
The instrument measures frequency from an AC
voltage (Vac) or AC current (Aac) signal. The instrument
detects each ‘0’ crossing of the signal, either ‘0 Vac’
or ‘0 Aac’. All available Vac and Aac signal ranges are
accepted as frequency input signal.
•
How to configure the instrument to measure frequency
To measure frequency from a Vac signal, select the internal
jumpers for the desired AC voltage range (see section 1.9), connect
the signal for the selected voltage range (see section 1.10), and
configure the instrument to measure frequency (see section 1.29.1).
The same applies to measure frequency from Aac signals. See
example at section below.
Ranges
of measure
Scale
by default
Scalable
AC signal
(see section 1.9)
Jumper
'T'
Response
time
Accuracy
(% reading)
15 to 100Hz
0/100.0 from 9999
to -1999
select Vac or
Aac range
4-5
70mSec.
<0.15% of
reading
Table 16 - Ranges of measure for frequency
•
Scaling
The default resolution is 0.1 Hz. The instrument allows to scale the
reading to 4 digits (9999 / -1999) with configurable decimal point
to any position. The ‘second scaling’ function can also be used (see
section 1.25).
•
Maximum and minimum signal
Frequency signals below 15 Hz are measured as ‘0’. Frequency
signals higher than 100 Hz are out of accuracy. Signals higher than
1000 Hz will read ‘display overflow’ ‘d.oVr’ error.
Ranges
of measure
Scale
by default
Scalable
Jumper ‘S’
(see section 1.9)
Jumper ‘T’
(
see section 1.9)
Accuracy
(%FS)
Max.
oversignal
Connection
(terminals)
Z
in
4/20 mA
passive
(needs Vexc.)
0/100.0
de 9999
a - 1999
D
1-2
<0.15%
25 mA
2 (signal)
5 (Vexc)
4.7 Ohm
active
4-5
2 (mA+)
4 (mA-)
0/10 Vdc
passive
(needs Vexc.)
A
1-2
<0.20%
25 Vdc
2 (+Vdc)
4 (comm.)
5 (Vexc)
1 M
active
4-5
2 (+Vdc)
4 (comm.)
Table 15 - Ranges of measure for process signals
•
Example
To measure the 50 Hz frequency from a 230 Vac
power line, select jumpers ‘GI’ for 600 Vac signal
range (see section 1.9), connect signal to terminals
‘1’ and ‘4’ (see section 1.10), and configure
‘frequency’ at the input signal configuration menu
(see section 1.29.1).
