Spectrum Controls 140 EHC 204 00sc - Manual (Page 43)

Quantum Series 140 EHC 204 00sc 140 EHC 208 00sc
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Counter Limit Flag: Bit 8
This flag indicates that the counters accumulator has reached its user-defined count limit.
When the Counter Limit word is in use, i.e. it has a value other than zero, then the Counter Range
flag indicates the counter is at the User defined limit. When the counter value is equal to the Limit
value the Counter Limit flag bit will be set until the Reset Flags Bit is set. If the Stop On Limit bit
is set the counter will not exceed the counter limit. If the Counter Limit function is not in use, i.e.
its value is zero, and then the Limit flag will never be set. This value is either 65,536 or 16,777,216
depending on the accumulator size selected.
Counter Zero Flag: Bit 7
The Counter Zero flag is set when the counter is reset to zero or counts down to zero. If the
Stop On Zero bit is set the counter will not roll until the Limit flag cleared. The Limit flag will stay
set until the Reset Flags bit is toggled in the channels’ configuration register.
Over Rate Flag: Bit 6
The over Rate flag is set when the input frequency exceeds its maximum range of 50KHz. This
flag indicates that the input counter rate is over the valid range of the module and that the value
indicated in the frequency data register may not be correct. This flag is normally set at 50kHz unless
a rate scale factor is used
Rate Limit: Bit 5
A user defined Rate Limit flag is active when the user has set the rate limit data register to a
limit value other than zero. When the rate value is greater then or equal to the limit value the Rate
Limit flag bit will be set indicating that the input rate is above its limit.
Rate Zero Flag: Bit 4
The Rate Zero flag is set when the input rate is zero. This flag can be used to flag an input fault
condition. Any input signal less than .5Hz will set the Zero rate flag.
K & M Factor Set Flag: Bit 3
This bit indicates that a non-zero K or M factor value has been written to the module EEPROM.
This value will be use to scale the input counter data. When a K or M factor is set all rate data will
be scaled by either one or both factors.
R Factor Set Flag: Bit 2
This bit indicates that a non-zero R factor value has been written to the modules EEPROM.
When a R factor is set all rate data will be divided by this factor.
Configuration Error Flag: Bit 1
This flag is set when the channel configuration word is set to an illegal state. An example
would be if one channel was configured for quadrature detection and its quadrature pair was not. In
this case both channels would have their configuration flags set until the configuration word was
corrected. All counter and rate data will be set to zero when an illegal configuration occurs.
Possible Configuration errors:
1. Range data between channel pairs in quad mode
2. Filter data between channel pairs in quad mode