Mitsubishi MELSEC-Q series User Manual page 42

3
SPECIFICATIONS
3
- 20 3.2 Function List
3.2.5 Scaling function
(1) Even if the digital value input range is enlarged, the resolution will not be more
than the one applied when the scaling function is not used. As the digital
value input range is narrowed, the resolution is lowered.
(2) When a digital value input range not including zero (0), such as "1000 to
6000", is specified, turn ON the output enable/disable flag after setting values
within the input range in the CH
If the output enable/disable flag is turned ON with the default value (0) set in
the CH digital value, an error will occur and an error code will be stored in
the Error code (Un\G19).
(3) The check of the settable range is performed for "digital values actually used
for D/A conversion".
(4) Depending on whether to use the scaling function or not, the analog output
value varies on the boundary between the inside and outside of the digital
input value setting range.
[Example 1]
Output range: 4 to 20mA, Normal resolution mode, and not using the scaling
function
By the conditions of the output range and resolution mode, the available
digital input value setting range is –96 to 4095.
When a digital value is the upper limit of the settable range, 4095 or higher, an
analog value equivalent to 4095 is output, which means the same analog
value is output for the digital values within and outside the setting range.
[Example 2]
Output range: 4 to 20mA, Normal resolution mode (same as Example 1), and
using the scaling function with:
Scaling upper limit value: 3000, Scaling lower limit value: 1000
When a digital value is the upper limit of the settable range, 3047 (4094 after
calculation), an analog value equivalent to 4094 is output.
On the other hand, if it is out of the settable range, which is 3048 or higher
(calculated value is 4096 or higher), an analog value equivalent to 4095 is
output.
As a result, the analog output value converted from the upper limit digital
value of the settable range is different from the one converted from the value
outside the settable range by 1 digit.
digital values (Un\G1 to Un\G6).