RN6065 RN6066
Absolute encoders with SSI interface
8
6 Operation
6.1 Data signals
Code signal data input:
TTL compatible signals, clock and clock (inv.) from driver to RS 422
Code signal data output:
Synchronous serial, TTL compatible signals data and data (inv.)
6.1.1 Triggering of a data word
T
13T
13
12
11
2
1
LSB
MSB
t1
t2
t3
1:
Clock
2:
Data
T = 1...10 μs / t1 ≤ 0,5 μs / t2 < 0,4 μs / t3 13...20 μs
In quiescent condition the clock and data lines are "high". The current measured value is stored with
the first falling clock edge. Data transfer begins with the first rising clock edge.
After transfer of a complete data word the data output remains low during the time t2, only then is the
encoder ready to transmit the next measured value. If during this time there is a new request for data
output (clock), the data which have already been provided are provided again.
In this case the data output is "low" between LSB (Least Significant Bit) of the first transfer and MSB
(Most Significant Bit) of the second transfer.
If the data output is interrupted ( ≤ t2), a new measured value is stored with the next clock edge. The
external electronics reads the data with the rising clock edge.
6.1.2 Level of the control inputs
When the control inputs Reset to zero and Reversal of the direction of rotation are used, the following
requirements for the signal levels have to be adhered to:
Inactive: LOW < 0,25 x U
b
/ Active: HIGH > 0,6 x U
b
Switching time: min. > 1 ms
Reversal of direction of rotation
By permanent application of L+ to pin 1, the direction of rotation for increasing position values is
reversed.
