Datasheet

Ip251_02b_oi_e.doc / Dez-15 Page 20 / 28
The subsequent drawing explains the timing with use of equidistant update mode with a SSI
Wait Time setting of 3 ms.
With equidistant operation mode, the SSI wait time setting is limited to maximum 90 ms.
 The shortest possible time for equidistant updating is 2 ms, due to
internal processing times (SSI Wait Time set to 0.001). While your PC
is communicating with the unit, it is even 5 ms.
 The time marks TM1 and TM2 shown in above diagram can be
displayed with the Monitor function of the PC operator software. It is
easy to understand that the sum of both times must be equal to the
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 RS232 encoder data. For
this, just set parameter “/Operand” to 00000
Parameter
Description
SSI Offset:
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 is subtracted from the SSI position reading,
which can also cause negative results. When the Round-Loop is active, SSI
Offset displaces the mechanical zero position, but always with only positive
results.
SSI Hold Polarity
Sets the polarity of the Hold signal on terminal 10
(active high or active low)
0 : Hold = High,
1 : Hold = Low,