Setting Parameters For The 1Ssi - Siemens SIMATIC ET 200S Operating Instructions Manual

1SSI

4.8 Setting parameters for the 1SSI

4.8 Setting parameters for the 1SSI
Overview
You set the parameters for the 1SSI by means of the GSD file for the ET 200S or using the
STEP 7 parameter assignment software. It is not possible to reassign the parameters by
means of the user program.
Depending on the mode that you selected, either of the following parameter sets from your
parameter assignment appear in the parameter assignment software:
• All parameters (standard mode), or
• A portion of the parameters (fast mode)
You can enter the following parameters (the default appears in bold):
Parameters
Group diagnostics
Detection
Encoder type
1
Gray/binary converter
1
Transmission rate
1 3
Monoflop time
1 2 3
Parity
Normalization
Number of trailing bits
1
Direction reversal
Total steps of the
absolute encoder
1
242
Value Range
Disable/enable
Free-wheeling/synchronous
No encoder / SSI-13 bits / SSI-14 bits,
SSI-16 bits / SSI-21 bits / SSI-24 bits /
SSI-25 bits
Gray/binary
125 kHz / 250 kHz /
500 kHz / 1 MHz / 1.5 MHz / 2 MHz
16 µs / 32 µs / 48 µs / 64 µs
None, odd, even
Off/on
0 to 15
Off/on
Encoder type 13 bits: 16 to 8192
•
Encoder type 14 bits: 16 to 16384
•
Encoder type 16 bits: 16 to 65536
•
Encoder type 21 bits: 16 to 2097152
•
Encoder type 24 bits: 16 to 16777216
•
Encoder type 25 bits: 16 to 33554432
•
Note
Enabling parameter
This parameter is irrelevant in isochrone mode and
is not evaluated.
No encoder: The encoder input is switched off.
Code supplied by the encoder
Note that the transmission rate affects the accuracy
and up-to-dateness of the encoder values.
The specification of the monoflop time is relevant
for free-wheeling encoder value detection.
See the vendor's technical specifications.
An assigned parity bit is included in the "Encoder
Type" parameter. If a 25-bit encoder is assigned
parity, then 26 bits are read from the encoder.
The bit following the LSB (least significant bit) is
evaluated as a parity bit. A parity error is reported
by means of the following feedback interfaces:
EXTF in fast mode
•
ERR_SSI in standard mode
•
–
The number of trailing bits must be specified.
–
If you find "Total steps - highword" and "Total steps
- lowword" in your parameter assignment software
instead of "Total steps", the following definition
applies:
Total steps = total steps lowword + total steps
highword x 2
16
Operating Instructions, 02/2007, A5E00124867-05
Technological Functions