Emerson Process Management Bristol Series 9110 User Manual
Page 30

Board Setup
3-6
CI-9110
Table 3-3 - Switch SW2 (2-5), Output Rate Of Change
SW2-5
SW2-4
SW2-3
SW2-2
Nominal
Rate Of Change, ±15%
Close Close Close Close 1.8
Min.
Full
Scale
Travel
Close
Close
Close
Open
5.5 Min. Full Scale Travel
Close
Close
Open
Close
11.0 Min. Full Scale Travel
Close
Close
Open
Open
16.5 Min. Full Scale Travel
Close
Open
Close
Close
21.9 Min. Full Scale Travel
Close
Open
Open
Close
32.9 Min. Full Scale Travel
Close
Open
Open
Open
38.3 Min. Full Scale Travel
Open
Close
Close
Open
43.8 Min. Full Scale Travel
Open
Close
Open
Open
60.3 Min. Full Scale Travel
Open
Open
Close
Close
65.85 Min. Full Scale Travel
Open
Open
Close
Open
69.4 Min. Full Scale Travel
3.7 ANALOG FAILURE MODES (Fail Hold & Fail Zero)
Analog models have an "Analog Fault Detector" feature which, when selected by jumpers on
the Termination Board, provides a selection of two failure modes, Fail Hold and fail Zero. In
the "Fail Hold" mode, the Analog Fault will stop the stepper motor at the last pressure
output value prior to the loss of the analog input signal. Note that the Guard terminals are
not available for external usage in this mode. The Fault Detector trip point for this mode is
factory set at 0.8 volts which corresponds to -5% of fullscale.
In the alternate "Fail Zero" mode, the Guard terminals are available for use with an
external signal. In this mode, the analog input signal is “enabled” by a signal at the Guard
terminal. If the input drops to zero while the Guard signal remains TRUE, the output will
also go to zero.
The selection of either failure mode is accomplished via two jumpers, W1 and W2. These
jumpers are located on the Termination Board as shown in Figure 3-2. These jumpers may
be plugged in position A or B; however, both jumpers must always be in the same position.
The configurations are selected as follows:
FAIL-HOLD MODE
(Both Jumpers in A position)
In the "A" position, a failure of the AI Command Input (value fails below 0%) causes the
pressure output to remain at the value of the last valid sampling period. This condition is
maintained until a normal AI is received.