Siemens SINAMICS G180 Installation And Operating Instructions Manual page 115

function automatically as PTC thermistor monitoring inputs. The selection bits "PTC X2:27"
and "PTC X2:28 indicate the PTC thermistor status.
NOTICE
Unsuitable evaluation unit
If the PTC thermistor for explosion proof motors or for safe isolation is not evaluated using
an ATEX-certified, safely isolated evaluation unit or the peripherals board, damage to the
inverter can occur.
Use an ATEX-certified, safely isolated evaluation unit or the peripherals board for safe
operation.
Digital inputs –X2:27, –X2:28 and –X2:29 as frequency or tachometer inputs
These digital inputs can be used as a frequency or tachometer input, for example, in the
following way.
● The field-oriented control at input ‑X25 / ‑X101 is not possible, e.g. if the n-sensor is installed
● Only one simple proximity switch with e.g. four impulses per revolution is available. The
● You connect a frequency-dependent setpoint generator of the type used for mining
Example applications for the digital inputs as frequency inputs:
● Proximity switch with NAMUR output or with PNP-3 wire output
● Two-channel digital tachometer with HTL output
Proximity switch with NAMUR output or with PNP-3 wire output
Figure 8-27
Installation and operating instructions Sinamics G180
Operating Instructions, 05/2013, 4BS0751-001
on the machine and there is a gearbox between machine and motor.
resolution for the field-oriented regulation is too small in this case. It is suitable for displays
or more precise speed regulation.
applications, for example.
PNP speed sensor
Operation
8.5 Special functions
113