Lika IF51, User Manual

Page: 48 / 56

IF51
The Figure below explains the timing with use of fixed updating cycles mode
when the
SSI Wait Time
item is set to 3 msec.
1msec 2msec 3msec
SSI-Telegram
Calculations
Auswertung
TM1
0msec
TM2
SSI-Telegram
SSI Wait Time = 3 msec
Analogue
Update Analogue
Update
NOTE
•
The shortest time allowed for fixed updating cycles is 1.3 msec, due to
internal processing times (
SSI Wait Time
set to 0.001).
•
The time marks TM1 and TM2 shown in the Figure above can be
displayed using the MONITOR function of the PC operator software. It is
easy to understand that the sum of both times must be equal to the
SSI
Wait Time
setting; otherwise you must increase the Baud rate or
choose a longer update cycle. The serial access codes are ,, :3 “ for TM1
and ,, :5 “ for TM2.
•
In critical cases you can reduce the internal processing times of the unit,
by omitting the conversion of serial RS-232 encoder data. For this, just
set parameter
/ Operand
to 00000.
SSI Offset
This register defines the electrical zero position of the encoder with respect to
the mechanical zero position. When the ROUND LOOP function is not active
(
Round Loop
= 0), the
SSI Offset
value is subtracted from the SSI position
reading, which can also cause negative results. When the ROUND LOOP function
is active,
SSI Offset
displaces the mechanical zero position, but always within
positive values only. See also
Round Loop
item and the relevant example.
SSI Set value
Applying a remote SET signal to the SET input (DIL switch terminal 10) results in
a temporary replacement of the SSI position value by the
SSI Set value
entered
here. This function allows easy testing and simulation of fixed analogue output
values while commissioning. See paragraph “7.4 SET input” on page 38.
MAN IF51 I_E 1.1.odt 10 - Parameter settings 48 / 56