Relay Outputs - Accusonic 8510+ series Reference Manual

2-6 Accusonic Model 8510+ Series Flowmeter
section, variable to be output, range, and output under fault condition, are all defined under Analog Output
parameters (for definitions see Chapter 7).
Under fault conditions, the outputs will go either to 4.00 mA or be held at the last good value, depending on
the choice under the parameter Hold on Error. On some systems a zero output can be selected.
Under conditions of under-range, an output will go to 4.00 mA.
Under conditions of over-range, an output will go to 20.00 mA.
When the flowmeter is taken out of measurement mode the output holds the last value.
For electrical characteristics see "Electronic Unit" Specifications, page 2-1.

Relay Outputs

The relays which have been installed can be allocated to any section and to any of the functions by setting
the Relay Output parameters described in Chapter 7. The logical operation for the different functions is:
Threshold Exceedance
The relay changes from its normal state when the value of the Flow or Level equals or exceeds the

Threshold parameter for more than the number of consecutive measurement cycles defined by the
Delay parameter.
The relay returns to its normal state if the value of the Flow or Level falls below the Threshold for

more than the number of consecutive measurement cycles defined by the Delay.
If the section fails, the relay remains at, or immediately returns to its normal state.

The Normal state (either energized or de-energized) can be selected by the parameter Polarity.

The value of the Threshold can be positive or negative (–99999 to +999999).

Note: In the logic, the value -6.00 is regarded as greater than -7.00.
Status Alarms
The relay changes from its normal state when the Fault state has been in existence for more than the

number of consecutive measurement cycles defined by the Delay parameter.
 The relay returns to its normal state immediately if the Fault state ceases.
The Normal state (either energized or de-energized) can be selected by the parameter Polarity.

Note. A fault state due to a path failure is declared when the path has failed to provide data for more than a
number of consecutive measurement cycles defined by the parameter Max Bad Measures. If the relay Delay is
set to a value greater than zero, the relay will not operate until after that delay, even though the fault state will
have already been in existence.
The purpose of this routine is to hide short term faults which are known to occur, and only to give

alarms for permanent faults.
Totalizer Relays
The relay changes from its normal state and returns 100 milliseconds later whenever the value for the

Volume has increased by one complete unit.
Only one operation of the relay can occur each measurement cycle.

Only one relay can be allocated to each Section and only one to the Sum of Sections for totalizer

pulses.