Self Initiated Auto Zero
Where frequent minor zero deviations are expected, the Compu-M self initiated auto zero feature may be
utilized to perform an automatic zero calibration whenever the material flow ceases.
Connect a dry contact activated by a material prefeed control device such as a prefeed motor,
material control gate, or valve to board B 1TB-1 and 2 of the Compu-M. The contact must be closed while the
material prefeed is stopped.
While this contact is closed and after sensing an empty running belt the Compu-M will perform an auto zero. If
the difference between the auto zero and the last operator initiated (routine) zero calibration is less than 2% of
the design Rate (P1), the Compu-M will accept the auto zero results.
If the difference between the auto zero and the last routine zero is greater than 2% of the design Rate, the
Compu-M will display [E9 - auto zero out of range] temporarily, reject the results of the auto zero attempt and
then resume normal operation.
If the alarm relay is set for auto zero (P20 = 3) , the relay is de-energized and the display flashes. The alarm
is in effect until an ’auto zero’ within range occurs, when a calibration is initiated, or when the rate exceeds
12% of design.
If the Compu-M displays [E9] after repeated auto zero attempts, the operator should perform a routine zero
calibration. Future auto zero attempts will be referenced to this new zero calibration.
The Compu-M will continue to perform auto zero calibrations until the prefeed activated contact connected to
TB1-1 and 2 is open. Any material totalized during a self initiated auto zero is added to the Compu-M total
and the remote total. The analog mA output will respond to any material measured during a self initiated
auto zero.
PL-516 43
To Next Page
Loading...
