Spectrum Controls SLC 500 User Manual page 39

In extended count mode (counts up to ±8M) the preset will be multiplied
NOTE
by 256 internally such that a user preset of 1000 will result in a preset of
25600. This allows the preset value to cover the whole ±8 million count
range.
In program scale factor mode, an M Factor is stored in the module's non- volatile
memory. If an M Factor is defined (not zero) then the data value output for the
counter value will be COUNT × (M Factor/10,000). A value of zero must be
written to the M Factor to disable this feature.
Figure 4-5. Limit/M Factor Word
Example:
An M Factor of 10,200 will increase the output count by 2%.
Output Count = Input Count * 10,200/10,000 Output Count = Input Count * 1.02
When the count size is extended to ±8M using Configuration Bit 11, the
NOTE
Counters Maximum flag is extended to ±8M. The counter Preset and Limit
values are also extended to ±8M. This means that the resolution of the
Preset and Limit values is set in blocks of 256 counts (8 bits). This allows
the preset and limit values to cover the whole ±8M bit range. Refer to the
applications section of this manual for more information about setting
limit and scale values.
Counter Limit/K Factor:
The counter limit mode is used in Normal operation mode. This input data word
is used in conjunction with the Scale/Limit Mode enable bit. When the counter
limit bit is set, the counter limit flag will be active. When the counter value is
greater than, or equal to, the Limit value the Counter Limit flag bit will be set. If
the Stop On Limit bit is set the counter will not exceed the counter limit.
When operating in standard count mode, if the K Factor x Count Limit is
NOTE
> 32767 a configuration error will occur.
In extended counter mode the limit will be multiplied by 256 internally
NOTE
such that a user limit of 1000 will result in a limit of 256,000.
In program scale factor mode, a K factor is stored in the module's non- volatile
memory. If a K Factor is defined (not zero) then the data value output for the
Chapter 4: Channel Configuration, Data, and Status
User's Manual Pub. 0300181-07 Rev. A
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