Spectrum Controls SLC 500 User Manual page 41

Chapter 4: Channel Configuration, Data, and Status
CTR8
I:e.28 to I:e.31
Figure 4-8. Data Words
Counter Data, High word:
This input data register contains the upper word of the counter's accumulator.
This register is a 16 bit word in binary 2's complement format. When operating
in the extended count mode, ±8M counts, the high word is equal to the counter
value/1,000 and the low word is the remainder. For example, a count of 40,123
would result in a high word equal to 40, and the low word equal to 123. The high
word = 40 and the low word = 123.
Figure 4-9. Counter High Word
This register is always zero when operating the standard (32 K) count mode.
Counter Data, Low word:
This input data register contains the lower word of the counter accumulator. This
register is a signed 16-bit word in binary 2's complement format and will allow
count values up to ±32 K. This word is used in conjunction with the counter's
upper output word when in the extended count mode. Bit 15 represents the sign
for each word. When the counter is operating in the extended mode, the low and
high words are used together to form a composite number that extends the
counter to ±8 M. The low word represents counts up to 1000 and the high word
represents counts that carry over 1000. (When the counter is configured in
Extended mode.)
Actual count = (Value of the high word × 1000) + (Value of the low word).
Figure 4-10. Counter Low Word
Rate Register Word
Refer to Appendix A for floating point rate mode.
CTR4
(N/A)
User's Manual Pub. 0300181-07 Rev. A
4-11
Scale/Limit Value
7 Channel MSW, LSW,
Rate Data, Status Reg