HEIDENHAIN PWM 8 - Manual (Page 75)

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17.3.3 Parameter P10 "sensor connection" with programmable SSI encoders
When HTL encoder supply is activated when operating with 1Vpp encoders with programmable
SSI interface, additionally the parameter "P10=SENSOR UMSYS" is available.
By means of the parameter P10 the operator can set the sensor connection at the encoder input
and at the encoder output.
The parameters P2 and P3 are not available with HTL
power supply.
If HTL power supply is active, the parameter P10 serves to
set the sensor connection at the encoder input and at the
encoder output of the interface board.
There are three different settings for the sensor connection:
auto
The PWM8 itself is responsible for the sensor connections, depending on the selected PWM8
MODE. In the PWM8 MODE "MEASURE U/I" the sensor connection is opened at the encode
input such that the sensor voltages can be measured. At the encoder output the sensor
connection is maintained; thus the voltage of the subsequent electronics is fed to the PWM8
on four lines. Owing to the double conductor cross section the voltage on the lines is reduced
In all other PWM8 MODEs there is a sensor connection at the encoder input and at the
encoder output (reduced voltage on the power supply lines owing to double conductor cross
section).
If the encoder is powered "EXTERNAL FROM CUSTOMER" (parameter P2), the sensor
connections are opened at the encoder input and at the encoder output. The subsequent
electronics can readjust the encoder supply voltage. if this feature is supported by the
subsequent electronics.
open The sensor connections at the encoder input and at the encoder output of the interface board
are open, i.e. the sensor lines are simply fed through PWM8.
This setting is required for 1Vpp encoders with programmable SSI interface and HTL power
supply (additional serial interface via the sensor lines). Under these circumstances (P9 =
„PROG SSI“) the PWM8 automatically set the parameter P10 to "OPEN".
connected The sensor lines at the encoder input and at the encoder output of the interface board are
connected, i.e. the encoder is also powered via the sensor lines (the voltage is reduced owing
to double conductor cross section).
Display of interfering signal:
A and B < 0.3 Vpp
Response time of the interface board t1 approx. 5 µs
Response time of the PWM8 display t2 > 1.2 µs