MAT2_
Data: 15/01/18
file: MAT2_ing.doc
Rev:2
pag 6/7
Output signals
The transducer must be connected to an instrument which has an SSI 24 bit interface with Gray or Binary
coding (according to the chosen transducer version) with negative numbers represented in both cases in
two’s complement. The following schematic shows the clock and data signals:
The data is read from the MSB to the LSB.
Once the reading cycle has been completed, it is necessary to wait at least t
m
(15
µ
s) before beginning a new
reading.
Admissible clock frequencies range from 32kHz to 1.5MHz but the actual maximum value depends upon also
the length of the connecting cable. In any case it is recommended to use a shielded twisted pair cable for the
clock and data signals.
In an environment which has noise, it can be useful to implement a verification on transmission errors by
executing a multiple reading cycle, i.e. after the first reading, initiate a second reading before t
m
has passed to
verify that the value has not changed meaning that both readings are the same. If in one of the two cycles the
value is corrupted by noise, the two values will be different and the reading must be repeated.
The data is a 24 (or 25 bit) right aligned, Binary (or Gray) coded.
Zero point setting
After the transducer has been positioned on the magnetic band, it is necessary to set the value to zero
otherwise the minimum value can be any value within the admissible range.
With the transducer fixed in position and correctly positioned on the magnetic band, by connecting the ZR
input to the positive wire, zero is assigned to the position in which the transducer is currently located. The
zero point that has been set will remain memorized by the system even after the instrument has been turned
off and will remain unvaried until a new point is set. The ZR input must return open (or closed towards GND)
after zeroing the value.
Note: the zeroing procedure must be repeated in case of substitution of the transducer or of the magnetic
band.
Setting the counting direction
Starting from the zero point, the data from the transducer will increase towards the left and decrease towards
the right (refer to the image on page 1). To change the counting direction connect the DIR input to the
positive wire.
