Saia-Burgess Controls AG
Manual for PCD2|3.W7x0
│ Document 26-
833 E
NG07 │ 2018-10-18
Hardware
1-5
1
Signal processing
Rd
Rd
Rd
Rs
Rs
Sense +
Supply -
Sense -
Signal -
The feed voltage across the jumper is dependent on the performance of the
voltage regulation, the jumper current, the length of the feed cable and the
temperature. For this reason, it is usual to attach a return wire to the jumper, to
feed the effective jumper voltage back to the analogue converter with zero current
if possible.
1.5
Signal processing
Block diagram
Rd
Rd
Rs
Rs
Sense +
Supply -
Sense -
Signal -
Supply
+ 10 VDC
Pre-
amplifier
+
-
A/D-
converter
Ref. +
Digital
filter
Ref. -
Postfilter
and
I/O-
interface
P
C
D
I/
O
-B
us
Gain
● Pre-amplification is by a factor of 16.3
● The reference voltage is reduced to 2.85 V by a voltage divider.
Amplification factor
The analogue converter is equipped with a further amplifier; the degree of
amplification is specified by the user. In general, the rule is:
GAIN = the nearest value less than [2.85 / (rating of call * 163)]
Rating
GAIN
Factor
0.5 mV / V
32
5
1 mV / V
6
4
2 mV / V
8
3
4 mV / V
4
2
Rating means: sensitivity of the cell (mV / V)
