Siemens SIMATIC ST-1500 Function Manual page 144

● 48 µs
● 64 µs
Note
If you select the "Automatic" option, the monoflop time automatically adapts to the encoder
used.
In isochronous mode, the "Automatic" option corresponds to a monoflop time of 64 µs. If the
monoflop time of the employed SSI absolute value encoder is less than 64 µs, you can
select the value of the encoder to achieve faster isochronous times.
Parity
With the parameter assignment of the parity, you specify whether the SSI absolute encoder
transfers a parity bit.
If, for example, a 25-bit encoder with parity is assigned, the technology module reads 26 bits.
The bit following the LSB (least significant bit) in the SSI frame is evaluated as a parity bit. A
parity error is reported in the feedback interface (Page 188) by means of the ENC_ERROR
bit.
Bit number LSB of the position value
This parameter is used to specify the bit number of the LSB (least significant bit) of the
position value in the frame of the SSI absolute encoder. In this way you limit the range in the
frame that supplies the position value.
The value must be less than the bit number of the MSB of the position value. The difference
between the bit numbers of the MSB and the LSB of the position value must be less than 31.
The default setting is "0".
Note
If you have selected the Code type "Gray", only the range from the LSB to the MSB of the
position value is converted to binary code.
Counting, measurement and position detection
Function Manual, 12/2017, A5E32009889-AG
Using the SSI_Absolute_Encoder technology object
4.4 Configuring SSI_Absolute_Encoder
143