AMALGAMATED INSTRUMENT PM4-SSI, Руководство по эксплуатации и инструкция, Страница: 25 / 36

5.29 Display scaling factor
Display:
SCLE
Range:
1
to any display value
Default Value:
1
The
SCLE
value is used together with the
INPt
value to calculate the value to be displayed from
the SSI input value transmitted from the encoder. These two functions are used to calculate the
display value and are used only when the alternative scaling methods of
U.SCL
and
USER SCLE
are both set to
OFF
. The scale factor can be set to any display value and the decimal point value
seen at this function will be set by the
dCPt
function.
If the relevant details of the encoder and display requirements are known the easiest way to find
the
INPt
and
SCLE
values is to use the maximum output value from the encoder as the
INPt
value and the display value for this maximum output value as the
SCLE
value. For example a 16
bit encoder has an output of 0 to 65535. If you wish this to display 0 to 1500 over the full range
of the encoder then set the
INPt
value to 65535 and the
SCLE
value to 1500.
The display value is calculated in the following manner:
Display value =
Value sent from encoder
×
SCLE
INPt
Example: A 12 bit SSI encoder will give an output in the range 0 to 4095 (if only positive values
are used). The display is to be scaled to show 0.0 to 359.9 over this 12 bit range. With 1 decimal
point the
INPt
value could be set to
4095
and the
SCLE
value set to
359.9
to achieve this
i.e. at one quarter output from the encoder (i.e. 1024) the display value is calculated from:
Display value =
1024
×
359.9
4095
i.e. Display value = 90.0
5.30 Number of input bits from encoder
Display:
SSI bits
Range:
1
to
31
Default Value:
1
Displays and selects the number of input bits which the display will interpret as incoming data.
This can be set from 1 to 31 bits. For example with an
INPt
of
1
and a
SCLE
of
1
and 12
bits selected the display will show from
0
to
4095
, i.e. the 12 bit binary number range, before
returning to
0
. Note: If the
SIGN
function is set to
on
then the maximum range displayed in
this example is
-2048
and
2047
. The table which follows gives some examples of the effect of
INPt
,
SCLE
,
SSI bitS
and
SIGN
settings.
PM4SSIMAN-2.2-0 25 of 36