Installation / Preparation for Commissioning
TR-Electronic GmbH 2020, All Rights Reserved
Printed in the Federal Republic of Germany
Page 24 of 91
TR-ECE-BA-GB-0163 v03
10/07/2020
3.4.1.2 HTL/TTL Level (optional)
Optionally, the incremental interface is also available with HTL and TTL levels. For technical reasons,
the user using this version has to take the following general conditions into account: ambient
temperature, cable length, cable capacitance, supply voltage, and output frequency.
In this case, the maximum output frequencies that can be reached via the incremental interface are a
function of the cable capacitance, the supply voltage and the ambient temperature. Therefore, the use
of this interface is reasonable only if the interface characteristics meet the technical requirements.
From the view of the measuring system, the transmission cable represents a capacitive load which
must be reloaded with each impulse. The load quantity required varies strongly depending on the
cable capacitance. It is this reloading of the cable capacitances that is responsible for the high power
dissipation and heat, which result in the measuring system.
The following diagrams show, separated by TTL and HTL version, the different dependencies with
respect to three different supply voltages.
TR’s own hybrid cable (part number: 64-200-021) was used for the measurements.
Figure 3: Cable lengths / cutoff frequencies, TTL version