Safety Function Characteristics - Honeywell SMARTLINE RM77 Supplementary Instructions Manual

SPECIFICATION OF SAFETY FUNCTION
6

6.2.3 Safety function characteristics

The safety function uses only a 4...20 mA analog output signal to measure the level and give the
device status. The analog output signal has an accuracy of ±2.5% of the 4...20 mA range.
WARNING!
The device must have the applicable options and settings for the application. The ambient and
process conditions must agree with the technical data given in the handbook (document [N1])
and this document (safety manual). You must obey the installation instructions given in the
handbook (document [N1]).
CAUTION!
We recommend that the 4 and 20 mA limits of the measuring range are not in the top dead zone
(100 mm / 3.9
The shape of the tank bottom can have a large effect on the accuracy when the tank is almost
empty. We recommend that device is not used to measure the liquid when it is less than 300 mm
from the bottom of the tank.
For more data about the top dead zone, refer to the"Operation" and "Technical Data" chapters in
the handbook (document [N1]).
Function input Function input
Function input Function input
Function output Function output
Function output Function output
If the device finds a fault:
Error signal Error signal
Error signal Error signal
If a logic solver is used, it must use low error alarm signals (current input ≤ 3.6 mA) to set itself
to a fail-safe condition.
18
¨ below the antenna).
None
4...20 mA
≤ 3.6 mA
www.honeywell.com/ps
SMARTLINE® RM77
34-VF-25-105 iss.1 GLO April 15 US