Maximum Fill Rates, Latching And Timeouts - Honeywell SmartLine SLG 700 User Manual

Maximum Fill Rates, Latching and Timeouts

The maximum fill rate, also referred to as Rate of Change (ROC) limits the expected level
changes between two successive measurements. Software revision prior to R200 allowed a
range of 4 - 20 cm/s. As of R200 this limit is increased to 90 cm/s. If a level is detected to
have moved further then the ROC limit, the level status is considered bad. See also Table 4-5:
Display Config sub-menu.
The Echo Lost Timeout setting is the number of seconds that the transmitter will wait after
the reflection from the product has been lost before setting a critical alarm and entering
failsafe (burnout) mode. The same behavior will result if instead of the measurement being
completely lost, the rate of change has been exceeded.
The latching mode parameter allows selecting the behavior of the GWR transmitter in case of
a measurement fault critical error. If the Latching option is selected, the GWR transmitter
will stay in the critical error state once the Echo Lost Timeout has expired, until a user
performs a hardware or software reset. The latching mode option has a significant effect on
behavior of the sensor when levels are considered lost. If the Non-latching option is selected,
the GWR transmitter will leave the critical error state automatically (after the Echo Lost
Timeout expires) and attempt to re-measure level over the entire probe length. Latching mode
can only be enabled with HART transmitters.
SLG 700 SmartLine Level Transmitter User's Manual
Page 20 Revision 8