Renishaw HS20 Installation Manual page 37

Signal strength
Depending on the type of quadrature required (analogue / digital), the way in which the signal strength
is measured may vary.
There are two methods of reading the signal strength from the HS20 as shown below:
• Digital signal strength output - The digital representation of the signal strength is also available
through the diagnostics connector in an RS485 format which can be connected to
the RCU10 and a live signal strength viewed within the RCU-CS software.
• Analogue signal strength output - The analogue representation of the signal strength is
available through the diagnostics connector in a 0 to 1V format that can be easily read with a
multi-meter.
Using digital quadrature
When the digital quadrature is used, the signal strength can be measured using the analogue or
digital signal strength output.
Using analogue quadrature
When analogue quadrature is used, it may be required that the signal strength is measured more
accurately. This is because the analogue and digital signal strength outputs are digitally generated
and 100% signal strength measured at these outputs represents a signal amplitude of
=> 0.42 Volts. This means that regardless of the actual signal amplitude, when it is > 0.42 Volts
then this will be shown as 100% from both the analogue and digital signal strength outputs as
shown within the chart below:
SIGNAL STRENGTH VS. ANALOGUE QUADRATURE
120%
100%
80%
60%
40%
20%
0%
Therefore to maximise the performance of the analogue quadrature by minimising interpolation
errors, it is recommend that the signal is maximised to 1V. This can be achieved by using a
oscilloscope on the analogue quadrature outputs to measure the true analogue signal amplitude.
ANALOGUE QUADRATURE (V)
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