Emerson Oxymitter 5000, Instruction Manual

Page: 67 / 226

Instruction Manual
IM-106-350, Rev 2.2
July 2008
3-5
Oxymitter 5000
Table 3-2. Logic I/O Parameters
Alarm
When configured as an alarm, this signal alerts you to an out-of-spec
condition. The output is 5 V in series with a 340 ohm resistor. For optimum
performance, Emerson Process Management recommends connecting the
output to a Potter & Brumfield 3.2 mA DC relay (P/N R10S-E1Y1-J1.0K).
Of the ten modes in Table 3-1, mode 0 through mode 7 are the alarm modes.
The factory default is mode 5 for Oxymitter 5000 units without an IMPS 4000
or SPS 4001B. In this mode, the output will signal when a unit alarm or a
CALIBRATION RECOMMENDED indication occurs.
Calibration Handshake Signal
If using an optional IMPS 4000 or SPS 4001B, the logic I/O must be
configured for calibration handshaking. Of the ten modes in Table 3-1, only
modes 8 and 9 are configured for calibration handshaking. For an Oxymitter
5000 with an IMPS 4000 or an SPS 4001B, the factory sets the default to
mode 8. In this mode, the logic I/O will be used to communicate between the
Oxymitter 5000 and sequencer and to signal the sequencer when a
CALIBRATION RECOMMENDATION indication occurs.
Recommended
Configuration
Fieldbus Signal Upon Critical Alarm
Emerson Process Management recommends that the factory default be
utilized. When a critical alarm occurs which causes the O
2
reading to become
unstable or unreliable, the Oxymitter will flag the O
2
reading. All further O
2
readings will be flagged as Out Of Service until the problem has been
corrected.
If the O
2
measurement is being utilized as part of an automatic control loop,
the loop should be placed into manual upon this failure event or other
appropriate action should be taken.
Calibration
Emerson Process Management recommends utilizing an autocalibration
system, actuated by the "calibration recommended" diagnostic. New O
2
cells
may operate for more than a year, but older cells may require recalibration
every few weeks as they near the end of their life. This strategy ensures that
the O
2
reading is always accurate, and eliminates many unnecessary
calibrations based on calendar days or weeks since previous calibration.
When utilizing the SPS 4001B or IMPS 4000, consider wiring some or all
associated alarm contacts.
Parameter Definition Range
Parameter
Number
IO_PIN_MODE This parameter represents the operating
mode of the discrete IO pin of the
transmitter.
1-10 40
IO_PIN_STATE This parameter represents the current state
of the transmitter’s discrete IO pin.
0=FALSE, 1=TRUE.
0-1 41