POSITIP 855 - heidenhain - DR. JOHANNES HEIDENHAIN GmbH

II - 5 Measured Value Output
II - 5
Measured Value Output
POSITIP can output measured values over the data interface.
Starting measured value output
There are three ways to start measured value output:
• Transmit control character to the data interface
• Send signal to switching input
• Signal from edge finder
The delay between the latch signal and measured value output
depends on the selected signal.
Transit time of encoder signals
After approximately 4 µs the encoder signals are present in a buffer
which is interrogated by the internal latch signal. The measured
value that is output is therefore the value that existed approximately
4 µs prior to the internal latch.
Starting measured value output with Ctrl B
t1: Delay between Ctrl B command and internal latch
t1 £ 0.5 ms
t2: Delay between internal latch and measured value output
t2 £ 30 ms + (5 ms · N)
N = number of rotary axes with Deg/Min/Sec display
t3: Time between end of data output and next latch with
Ctrl B
t3 ³ 0 ms
tD: Duration of measured value output
The duration of measured value output (tD) depends on:
• The selected baud rate (BR)
• The number of axes (M)
• The number of blank lines (L)
176 · M + L · 11
tD = BR
[s]
Ctrl B Ctrl B
Fig. 45: Time diagram for measured value
output with Ctrl B
102 Technical Information POSITIP 855
RXD
TXD
t 1
t 2
t D
t 3