Product overview
KL3356
12
Version: 2.3.0
Operation mode
Comment
Normal operation
Measuring the force acting on the load cell
Zero calibration
The DC voltage potential at the inputs to the operational amplifier corresponds to that of
normal operation. The differential voltage at the two operational amplifier inputs is 0 mV
(determination of the zero points).
Final calibration
The DC voltage potential at the inputs to the operational amplifier corresponds to that of
normal operation. The divided cell supply voltage (R114, R115, R151) is applied as a
differential signal to both the operational amplifier inputs (determination of the
amplification factors).
Null-test (0 V)
The DC voltage potential at the operational amplifier inputs is set to 0 V. The differential
voltage at the two operational amplifier inputs is 0 mV (first stage in establishing the
Common Mode Rejection of the operational amplifiers).
Null-test (2.5 V)
The DC voltage potential at the operational amplifier inputs is set to 2.5 V. The
differential voltage at the two operational amplifier inputs is 0 mV (second stage in
establishing the Common Mode Rejection of the operational amplifiers).
Reference test
The DC voltage potential at the inputs to the operational amplifier corresponds to that of
half the reference voltage. The divided reference voltage (R114, R115, R151) is applied
as a differential signal to the two operational amplifier inputs (measurement of the
reference voltage).
Switch settings
The various operation modes are selected by means of internal switches:
• Switch SW1 is switched by bit
of the feature register, and is to be closed for all calibration
processes:
- R32.7 = 0: SW1 open
- R32.7 = 1: SW1 closed
• If manual calibration mode is enabled in the command register
you can control switches
SW2 to SW8 by means of the output data word
Operation mode
RegOUT
Switch settings
SW1
SW2
SW3
SW4
SW5
SW6
SW7
SW8
Normal operation
0
dec
0 / 1
1
1
0
1
0
1
0
Zero calibration
1
dec
0 / 1
0
1
1
0
0
0
0
Final calibration
2
dec
0 / 1
0
0
1
1
0
1
0
Null-test (0 V)
3
dec
0 / 1
0
0
1
0
0
0
1
Null-test (2.5 V)
4
dec
0 / 1
0
0
1
0
1
0
0
Reference test
5
dec
0 / 1
0
0
1
0
1
0
1
Key
0: switch not connected
1: Switch connected
Calibrating the measuring amplifiers
The measuring amplifiers are periodically subjected to examination and calibration. For this purpose a total
of eight analog switches are provided in order to be able to connect the various calibration signals. It is
important for this process that the entire signal path, including all passive components, is examined at every
phase of the calibration. Only the interference suppression elements (L/C combination) and the analog
switches themselves cannot be examined.
The calibration interval is set in register
Summary of Contents for KL3356
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