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ME15 Magnetic Encoder Manual
Revision 1.1
ME15 SSI OPTION
Supply Voltage……………………5 - 30VDC (+/- 5%)
Power Consumption……………….< 0.5W
Measuring Range……………….…360
°
.
Resolution/Code…………………..10 Bit / Binary
Position Accuracy…………………0.5
°
Linearity……………………………< 0.5%
Repeat Accuracy…………………...< 0.1%
SSI Interface:
Clock Frequency………………….100 KHz – 1 MHz
Output Driver……………………..RS 485 (TIA/EIA Compliant)
Short circuit proof outputs:……….Yes
∗
∗
Short circuit to 0V (DC Return) or to output, when supply voltage is correctly applied.
The M15 SSI device has two options of operation:
Standalone Option
or
Multiplexing Option
. When M15 works as
Standalone SSI device, data is continuously read-out by simply applying SSI Clock signal with Enable line pulled low
(i.e. tied to the DC Return). When M15 works as Multiplexing SSI device, Enable line determines whether particular
M15’s input/output driver is enabled (Enable Input low) or disabled (Enable Input high). Only one unit at the time is
supposed to be enabled and all others disabled.
SSI Protocol
The serial data transmission timing is outlined in Figure 1: With the first falling edge of the clock (
CLK
) signal, data is
latched into the output shift register. Each subsequent rising
CLK
edge shifts out one bit data.
The serial word contains 16 bits. The first 10 bits
D[9:0]
are the absolute angular position data (
MSB
is clocked out
first). The subsequent 6 bits contain system information; about validity of data such as
OCF
(
O
ffset
C
ompensation
F
inished),
COF
(
C
ordic
O
ver
f
low),
LIN (Lin
earity Alarm),
P
arity and
M
agnetic
F
ield status (increase / decrease / out
of range) and they are used for diagnostic purposes only.
Figure 1: Synchronous serial interface with absolute angular position data
