UMAX130511 Version 1.00A Preliminary Documentation
– May be subject to change
20 - 141
It is the
AI Input FV
which is used by the application for error detection, and as a control signal for
other logic blocks (i.e. output control.) Object 7100h is mappable to a TPDO and is mapped to
TPDO1 by default.
Read-only object 7130h
AI Input Process Value
is also mappable. However, the default values for
objects 7121h
AI Scaling 1 PV
and 7123h
AI Scaling 2 PV
are set to equal 7120h and 7122h
respectively, while object 6132h
AI Decimal Digits PV
is automatically initialize to equal 2102h.
This means that the default relationship between the FV and PV is one-to-one, so object 7130h is
not mapped to a TPDO by default.
Should a different linear relationship between what is measured versus what is sent to the
CANopen bus be desired, objects 6132h, 7121h and 7123h can be changed. The linear
relationship profile is shown in Figure 7 below. Should a non-linear response be desired, the
lookup table function block can be used instead, as described in Section 1.6.
Figure 8
– Analog Input Linear Scaling FV to PV
As stated earlier, the FV scaling objects are automatically updated with the Sensor Type or Range
changes. This is because objects 7120h and 7122h are not only used in a linear conversion from
FV to PV as described above, but also as the minimum and maximum limits when the input is used
to control another logic block. Therefore, the values in these objects are important, even when the
AI Input PV object is not being used.
The AI Span Start and AI Span End objects are used for fault detection, so they too are
automatically updated for sensible values as the Type/Range changes. The Error Clear Hysteresis
object is also updated, as it too is measured in the same unit as the AI Input FV object.
Table 9 lists the default values that are loaded into objects 7120h, 7122h, 7148h, 7149h, and
2111h for each Sensor Type and Pulses per Rev combination. Recall that these objects all have
the decimal digits applied to them as outlined in Table 10.
Sensor Type/
Input Range
7148h
AI Span Start
(i.e. Error
Min)
7120h
AI Scaling 1
FV
(i.e. Input
Min)
7122h
AI Scaling 2 FV
(i.e. Input Max)
7149h
AI Span End
(i.e. Error Max)
2111h
Error Clear
Hysteresis
Voltage: 0 to 5V
200 [mV]
500 [mV]
4500 [mV]
4800 [mV]
100 [mV]
Voltage: 0 to 10V
200 [mV]
500 [mV]
9500 [mV]
9800 [mV]
200 [mV]
Voltage: -5V to 5V
-4800 [mV]
-4500 [mV]
4500 [mV]
4800 [mV]
200 [mV]
Voltage: -10V to 10V
-9800 [mV]
-9500 [mV]
9500 [mV]
9800 [mV]
400 [mV]