Technical data
12
8LVA user's manual V1.0
2.2 Motor encoder systems
General
Motors in the 8LV series are available with EnDat encoders as well as resolvers. The encoder system is listed as
part of the model number in the form of a 2-digit code (
ee
).
Analog and digital transfer
A resolver is an analog encoder system. Resolvers are particularly robust against vibrations and high operating
temperatures. A disadvantage is the low accuracy of 6-10 arcmin. Furthermore, no multi-turn variant with resolvers
is possible.
Digital encoders use a serial transfer protocol. This protocol is called EnDat. The EnDat protocol is a developed
standard that incorporates the advantages of absolute and incremental position measurement and also offers a
read/write parameter memory in the encoder. The embedded parameter chip is stored by B&R in this encoder
memory. This data and the B&R ACOPOS systems form a plug-and-play drive solution. Absolute positioning can be
used within a revolution with the single-turn variants. A homing procedure is not required because of the absolute
position measurement. For applications where the motor covers several revolutions for positioning, a multi-turn
encoder that can save up to 65535 revolutions can be used. A solution with a single-turn encoder variant with a
homing procedure is also possible.
2.2.1 EnDat 2.2
For the advanced, fully digital EnDat 2.2 protocol, the positions are generated directly in the encoder and commu-
nicated serially with the drive system. This transfer is very robust in relation to disturbances and is even certified
for safety applications.
2.2.2 Resolver
General information
RE-15-1-J04 resolvers are used in the motors.
Technical data
Encoder type / Order code (ee)
R0
Precision
10 angular minutes
Vibration during operation
10 < f ≤ 500 Hz
≤500 m/s²
Shock during operation
Duration 11 ms
≤1,000 m/s²
2.2.3 EnDat 2.2 encoder
For the advanced, fully digital EnDat 2.2 protocol, the positions are generated directly in the encoder and commu-
nicated serially with the drive system. This transfer is very robust in relation to disturbances and is even certified
for safety applications.
General information
Digital drive systems and position control loops require fast and highly secure transfer of data obtained from position
measuring instruments. In addition, other data such as drive-specific characteristics, correction tables, etc. should
also be available. To ensure a high level of system security, measuring instruments must be integrated in routines
for detecting errors and be able to perform diagnostics.
The EnDat interface from HEIDENHAIN is a digital, bidirectional interface for measuring instruments. It is able
to output position values from incremental and absolute measuring instruments and can also read and update
information on the measuring instrument or store new data there. Because it relies on serial data transfer, only 4
signal lines are needed. Data is transferred synchronously to the clock signal defined by the subsequent electronics.
The type of transfer used (e.g. for position values, parameters, diagnostics, etc.) is selected using mode commands
sent to the measuring instrument by the subsequent electronics.
