Overflow Monitoring
(Original Document)
About us
Introduction
The TSX AEY 810 module allows the user to select between 6 voltage or current ranges for each input. Whichever range is selected, the module always checks for overflow: it ensures that the measurement falls between a lower and an upper threshold.
This control is optional.
The module typically tolerates a 5% overflow of the positive current range covered.
Measurement Areas
The measurement range is divided into 5 areas: 
Nominal Area
Measurement range matching the chosen range. 
Upper Tolerance Area
Values included between the maximum value for the range (for instance: + 10 V for the -10 V +10 V range) and the upper threshold. 
Lower Tolerance Area
Values included between the minimum value for the range (for instance: - 10 V for the -10 V +10 V range) and the lower threshold. 
Overflow Area
Area located beyond the upper threshold. 
Underflow Area
Area located below the lower threshold.
Overflow Flags
In over/underflow areas, there is a risk of saturating the measurement device. In order to counter this risk through the user program, error bits have been prepared:
Bit Name
Meaning (when = 1)
%IWr.m.c.1.5
Measurement in Lower Tolerance Area
%IWr.m.c.1.6
Measurement in Upper Tolerance Area
%MWr.m.c.2.1
If over/underflow control is required, this bit indicates any offending variation from range :
  • %MWr.m.c.2.14 denotes an underflow,
  • while %MWr.m.c.2.15 denotes an overflow.
%Ir.m.c.ERR
Channel Fault.
NOTE: During an under/overflow, peaks in the measured value are suppressed, so that said value meets the matching threshold.
Values for Under/Overflow Thresholds
Values for those thresholds are configurable independently from one another. They may assume integer values between the following limits:
The following table provides Tolerance Area Values, based on the different ranges:
Range
Lower Tolerance Area
Upper Tolerance Area
-
Default Value
Maximum Value
Min. Value
Default Value
Min. Value
Maximum Value
Bipolar
-0,125 x Δrange/2
0
-0,25 x Δrange/2
-0,125 x Δrange/2
0
0,25 x Δrange/2
Unipolar
-0,125 x Δrange
0
-0,25 x Δrange
0,125 x Δrange
0
0,25 x Δrange
Normalized Bipolar
-1250
0
-2500
1250
0
2500
Normalized Unipolar
-1250
0
-2500
1250
0
2500
User Bipolar
-0,125 x Δrange/2
0
-0,25 x Δrange/2
0,125 x Δrange/2
0
0,25 x Δrange/2
User Unipolar
-0,125 x Δrange
0
-0,25 x Δrange
0,125 x Δrange
0
0,25 x Δrange
Legend:
Δrange
Range Upper Value - Range Lower Value
NOTE: The bipolar range is the +/-10V range. Unipolar ranges are the following: 0...20mA, 0...10V, 0...5V, 1...5V, and 4...20mA.
Overflow Monitoring is enabled by default, but it may also be partially enabled (only for under- and overflows), or disabled.
Example
Overflow for the 4...20 mA range in normalized mode, on the 0 (zero) channel: 
1
Underflow Area. 
2
Lower Tolerance Area 
3
Nominal Area. 
4
Upper Tolerance Area 
5
Overflow Area