Table of Contents
Advertisement
Parameter P2: U-MSYS EXTERN
Note: Parameter P2 is only effective, if the encoder is powered externally (= by a subsequent electronics,
e.g. a counter, a control or customer electronics). In this case PWM 8 can be switched to EXTernal
power supply of the encoder in the Options soft-key row:
If the encoder is powered EXTERNALLY, parameter 2 serves to choose whether the encoder supply of the
subsequent electronics is to be
• floating with relation to PWM 8 (potential segregation)
(parameter setting: FLOATING), or
• directly fed to the encoder without being changed by PWM 8
(parameter setting: FROM CUSTOMER).
Special feature of HTL interface board:
When using a HTL interface board, parameter P2 is not available. The measuring system
can only be powered with the potential of the subsequent electronics. Potential segregation is not possible!
Why is potential segregation required between PWM 8 and subsequent electronics?
Owing to different reference potentials of the encoder signals 11µApp/1Vpp (U
(0V) the signals may be shifted, which can cause counting errors in the subsequent electronics and in the
most unfavorable case result in a measuring circuit error. Potential segregation avoids signal shifts and
ensures that the encoder circuit operates correctly, when PWM 8 is switched on.
Notes on floating encoder supply from the subsequent electronics:
(Parameter P2: FLOATING)
1. To ensure trouble-free functioning of subsequent electronics with 11µApp and 1Vpp
encoder inputs.
2. In the PWM 8 the power supply of the encoder is generated by a switching regulator, providing 5.0V
(standard setting) irrespective of the encoder power supply of the subsequent electronics. If required, the
encoder voltage can be set manually.
For this purpose the soft keys
available.
Note on HTL interface boards:
When using a HTL interface board the standard setting of the encoder voltage is 12V, if there is no supply
voltage of the subsequent electronics at the OUT flange socket of the interface board. If there is a
voltage, PWM 8 "connects" the HTL encoder voltage to the encoder voltage of the subsequent
electronics. With HTL interface boards potential segregation is not possible.
3. The current intensity of the encoder voltage is set to 500 mA; if the terminating resistors (with TTL and
HTL interface boards) are switched on, it is 700 mA.
4. Owing to potential segregation the power consumption of the encoder supply by the subsequent
electronics is approx. 50% higher than it would be without potential segregation (due to the efficiency of
the DC/DC converter and the switching regulator). Please also note the increased voltage drop on the
encoder supply line caused by the higher current intensity!
[FLOATING, FROM CUSTOMER]
Soft key to switch to EXTernal power supply of the enocder.
This soft key is only displayed, if an encoder voltage of a
subsequent electronics has been connected to the encoder
output of the interface board.
Shown setting: encoder is powered externally.
in the soft-key row of the EXPERT MODE are
- 26 -
) and the interface boards
0
Advertisement
Table of Contents
