HEIDENHAIN PWM 20 - Manual (Page 232)

November 2014 Interface description 233
Parameters and
memory areas The encoder provides several memory areas for parameters. These can be read from by the
subsequent electronics, and some can be written to by the encoder manufacturer, the OEM, or
even the end user. Certain memory areas can be write-protected.
Parameters of the encoder manufacturer
This write-protected memory area contains all information specific to the encoder, such as
encoder type (linear/angular, singleturn/multiturn, etc.), signal periods, position values per
revolution, transmission format of position values, direction of rotation, maximum speed,
accuracy dependent on shaft speeds, warnings and alarms, ID number and serial number.
This information forms the basis for automatic configuration A separate memory area contains
the parameters typical for EnDat 2.2, such as status of additional data, temperature,
acceleration, support of diagnostic and error messages.
OEM parameters
In this freely definable memory area, the OEM can store his information, e.g. the “electronic
ID label” of the motor in which the encoder is integrated, indicating the motor model, maximum
current rating, etc.
Operating parameters
This area is available for a datum shift, the configuration of diagnostics and for instructions.
It can be protected against overwriting.
Operating status
This memory area provides detailed alarms or warnings for diagnostic purposes. Here it is also
possible to activate write protection for the OEM parameter and operating parameter memory
areas, and to interrogate their status. Once activated, the write protection can be reversed only
by HEIDENHAIN service personnel.
Note
The parameters, which in most cases are set by the OEM, largely define the function of the
encoder and the EnDat interface. When the encoder is exchanged, it is therefore essential
that its parameter settings are correct. Attempts to configure machines without including
OEM data can result in malfunctions. If there is any doubt as to the correct parameter
settings, the OEM should be consulted.