89
I/O
Modules
Note.
The instrument detects the type of module fitted in each position automatically.
Fig. 4.16 I/O Module Configuration
4.7
I/O Module Configuration
4.7.1
Analog Inputs
Set the Mains rejection frequency used to filter electrical
noise induced on the signal lines by power supply cables.
Note.
If the Mains rejection frequency is changed, the
instrument must be powered down and powered up again in
order to restore the inputs.
Input Adjustment
Inputs can be fine-tuned to remove process offset errors or
system scale errors.
Notes.
• Input adjustment frames appear only if recording is
enabled during configuration – i.e. the 'Disable recording
in configuration' check box is
not
ticked on entry to the
Configuration level – see Fig. 4.1, page 45.
• Changes to the Analog Input Type (Section 4.6.2) must be
saved to the current configuration before commencing
input adjustment.
Actual value / Desired value
1) Adjust the process or simulated input signal to a known
value below 50% of the engineering range.
2) If 'Actual value' (in engineering units) is different from
expected, set 'Desired value' to the correct value ('Offset
adjust' and 'Span adjust' values are calculated
automatically).
3) Repeat steps 1 and 2 for a value above 50% of the
engineering range.
4) Repeat steps 1 to 3 for each input.
Reset adjustment
Select to reset 'Offset adjust' and 'Span adjust' (see next
page) to zero and to 1 respectively.
4
CONFIGURATION…