Other signal modules
7.4 Position decoder module SM 338; POS-INPUT; (6ES7338-4BC01-0AB0)
S7-300 Automation System Module data
Manual, 08/2006, A5E00105505-04
7-15
Note
The Freeze function is acknowledged automatically when you assign new parameters with
different arguments to the relevant
channel.
The freeze function remains unaffected if you set parameters with identical arguments.
See also
SM 338; POS-INPUT addressing (Page 7-16)
SM 338; POS-INPUT programming (Page 7-15)
7.4.3 SM 338; POS-INPUT programming
Programming
You program the SM 338; POS-INPUT in
STEP 7
. Always program the module while the
CPU is in STOP mode.
After you completed the parameter declaration, download the parameters from the PG to the
CPU. At its next STOP → RUN transition, the CPU transfers the parameters to the SM 338.
New parameters can not be assigned by the user program.
Parameters of SM 338; POS-INPUT
The table below provides an overview of configurable parameters and defaults for the SM
338.
The defaults apply if you have not set any parameters in
STEP 7
(default setting bold).
Table 7-3 Parameters of SM 338; POS-INPUT
Parameters Range of values Note
Enable
• Fast-Mode
Yes / no
Enable parameter.
Applies to all 3 channels.
Enable
• Diagnostic interrupt
Yes / no
Enable parameter.
Applies to all 3 channels.
Absolute value encoder (SSI)
1)
none; 13 bits; 21 bits; 25 bits none: The encoder input is switched
off.
Code type
1)
Gray; Binary Code returned by the encoder.
Transmission rate
1) ,3)
125 kHz; 250 kHz; 500 kHz; 1 MHz Data transfer rate of the SSI position
detection. Observe the relationship
between cable lengths and the
transmission rate (see Technical data)